Graphing is a good method when you have small integers or fractions as your slope.
Substitution is a good method when you have two equations, and when one of the coefficient of the variables is one.
Linear combinations is a good method when you have the same coefficient for the same variable in 2 different equations.
use the volume equation and add all the numbers to it
Answer:
x = 
Step-by-step explanation:
Applying altitude- on - hypotenuse theorem.
(leg of large Δ )² = ( part of hypotenuse below it ) × ( whole hypotenuse )
x² = 3 × (3 + 7) = 3 × 10 = 30 ( take square root of both sides )
x = 
-3x + 5y = -9
4x + 8y = 12
Simplify the second,
x + 2y = 3
Times three,
3x + 6y = 9
Add to the first equation,
11y = 0
y = 0
-3x + 5(0) = -9
x = 3
Answer: x=3, y=0