Latihan Soal Matematika Smp Kelas 7

Explanation
To solve this expression, we need to follow the order of operations, which is parentheses, multiplication/division (from left to right), and addition/subtraction (from left to right). First, we simplify the expression inside the parentheses: -4 + 10 = 6. Then, we divide 6 by 2, which gives us 3. Finally, we multiply 3 by -5, resulting in -15. Therefore, the correct answer is -15, not -29.

Explanation
The question states that the temperature at place A is 60°C below zero and the temperature at place B is 280°C above zero. The temperature at place C is said to be between the temperatures at places A and B. Since place A is below zero and place B is above zero, the temperature at place C must be positive. The only positive temperature given as an option is 110°C, so that is the correct answer.

Explanation
The given statement is false. The scale on the map is 1:3,500,000, and the distance between the two cities on the map is 5 cm. To find the actual distance between the cities, we need to multiply the map distance by the scale. Therefore, the actual distance between the cities is 5 cm * 3,500,000 = 17,500,000 cm. Converting this to kilometers, the actual distance between the cities is 175 km, not 185 km.

Explanation
The distance covered by the wheel is directly proportional to the number of rotations. In this case, we know that after 18 rotations, the wheel covers a distance of 27 meters. Therefore, for 12 rotations, the distance covered would be proportional and can be calculated using the formula: (12 rotations / 18 rotations) * 27 meters = 18 meters.

Explanation
Jumlah penghuni asrama bertambah 10 orang, sehingga total penghuni menjadi 30 + 10 = 40 orang. Persediaan makanan yang ada sebelumnya cukup untuk 30 orang selama 8 hari. Namun, dengan penambahan penghuni, persediaan makanan akan habis lebih cepat. Oleh karena itu, dengan jumlah penghuni 40 orang, persediaan makanan akan habis dalam waktu yang lebih singkat, yaitu 6 hari.

Explanation
The cost of purchasing 1.5 dozen books is Rp72,000.00. If the books are sold individually at Rp5,000.00 each, the total revenue would be Rp90,000.00. To calculate the profit or loss percentage, we need to find the difference between the revenue and the cost, which is Rp90,000.00 - Rp72,000.00 = Rp18,000.00. The profit percentage is then (Rp18,000.00 / Rp72,000.00) * 100% = 25%. Therefore, the answer is "untung 25%".

Explanation
The correct answer is Rp5.000.000,00. The question states that the merchant incurs a loss of 16% when selling at a price of Rp4.200.000,00. To determine the cost price, we need to find the amount that represents 100% of the cost. To do this, we can use the formula: (selling price / (100% - loss percentage)) * 100%. Plugging in the given values, we get (Rp4.200.000,00 / (100% - 16%)) * 100% = (Rp4.200.000,00 / 84%) * 100% = Rp5.000.000,00. Therefore, the cost price is Rp5.000.000,00.

Explanation
Dinda menabung uang sebesar Rp2.000.000,00 di Bank dengan bunga 18% per tahun. Jumlah tabungan Dinda setelah 8 bulan dapat dihitung dengan menggunakan rumus bunga sederhana, yaitu A = P + (P * r * t), dimana A adalah jumlah akhir tabungan, P adalah jumlah awal tabungan, r adalah tingkat bunga per periode, dan t adalah jumlah periode. Dalam kasus ini, P = Rp2.000.000, r = 18% = 0.18, dan t = 8/12 = 2/3 (karena 8 bulan adalah 2/3 tahun). Menggantikan nilai-nilai tersebut ke dalam rumus, kita dapat menghitung A = Rp2.000.000 + (Rp2.000.000 * 0.18 * 2/3) = Rp2.240.000,00.

Explanation
The given sequence starts with the number 8 and increases by 5 each time. Therefore, the formula for the nth term of the sequence can be written as 5n + 3.

Explanation
The given expression is a multiplication of two binomials. To find the result, we can use the FOIL method, which stands for First, Outer, Inner, Last. Multiplying the first terms of each binomial, we get 4a^2. Multiplying the outer terms, we get -28ab. Multiplying the inner terms, we get -14ab. Multiplying the last terms, we get 14b^2. Combining like terms, we have 4a^2 - 30ab + 14b^2. Therefore, the correct answer is 4a^2 - 30ab + 14b^2.