X = original amount of water
x - 8(6) = 132
x - 48 = 132
x = 132 + 48
x = 180...it originally contained 180 gallons
3x-4 is the answer, you have to see that if its 3 times her nieces age it would be 3x and if its four less than that it is 3x-4
Answer:
924 cm²
Step-by-step explanation:
The surface area is equal to the area of the two triangles + area of the three rectangles.
Area of two triangles:
12 × (9+5) × 1/2
= 84
84(2) = 168
Area of the three rectangles:
15 × 20 + 13 × 20 + 14 × 20
= 840
840 + 84
The surface area of the triangular prism is 924 cm².
