Answer:
not sure for the 1st one but pretty sure 2nd one is B
Step-by-step explanation:
Answer:
Step-by-step explanation:

Add 5 to both sides

x = 6

Add 3 to both sides
x = -15 +3
x = -12
6x5+24x3+3x3+12x ------> Simplify by adding like terms
6x5 + 27x3 + 12x
Answer:
644 cm²
Step-by-step explanation:
Surface area of the composite figure = surface area of the large rectangular prism + surface area of the small rectangular prism - 2(area of the surface of the small rectangular prism that joins the larger prism)
✔️Surface area of the large rectangular prism = 2(LW + LH + WH)
L = 6 cm
W = 5 cm
H = 20 cm
Surface area = 2(6*5 + 6*20 + 5*20)
= 500 cm²
✔️Surface area of the small rectangular prism = 2(LW + LH + WH)
L = 6 cm
W = 4 cm
H = 12 cm
Surface area = 2(6*4 + 6*12 + 4*12)
= 288 cm²
✔️area of the surface of the small rectangular prism that joins the larger prism = L*W
L = 12 cm
W = 6 cm
Area = 12*6
= 72 cm²
✅Surface area of the composite figure = 500 + 288 - 2(72)
= 644 cm²