Answer:
surface area = 2(5 × 4) + 2(15 × 4) + 2(15 × 5) = 310 mm²
7(k + 2)
= 7×k + 7×2
= 7k + 14
12(3d + 12)
= 12×3d + 12×12
= 36d + 144
surface area rectangular prism = 2(4 × 5) + 2(15 × 4) + 2(15 × 5) = 310 cm²
5x + 7x - 2
= 12x - 2
4 + 3g - g + 2g
= 4g + 4
2 + 4g + 7g + 5
= 11g + 7