The volume of a triangular prism is V = 1/2 x a x c x h where a is height of the triangle, c is the base of the triangle and h is the height of the prism.
120 = 1/2 x a x c x h; we write a from the previous equation in terms of c and h thus,
a = 240 / ( c x h)
If the dimensions where halved then a = a/2 ; c = c/2 ; h=h/2
We use the volume formula again and substitute the given values to find the new volume,
V = 1/2 x a/2 x c/2 x h/2
Substitute the previously determined a term,
V = 1/2 x (240/2ch) x c/2 x h/2
We cancel and evaluate the constants therefore the new volume is,
V= 15 cm^3

3 0

3 years ago

Solve the equation -4x + 7 y equals 20. Y=3x+15

satela [25.4K]

Substitue what y equals for y and solve.

$-4x+7(3x+15)=20 \\-4x+27x+105=20 \\23x=-85 \\x=-\boxed{\frac{85}{23}}$

Hope this helps.

3 0

2 years ago