Step-by-step explanation:
start with 390 000x 5.6 x 6
<span>Simplifying
-15x2 + -2x + 8 = 0
Reorder the terms:
8 + -2x + -15x2 = 0
Solving
8 + -2x + -15x2 = 0
Solving for variable 'x'.
Factor a trinomial.
(2 + -3x)(4 + 5x) = 0
Subproblem 1Set the factor '(2 + -3x)' equal to zero and attempt to solve:
Simplifying
2 + -3x = 0
Solving
2 + -3x = 0
Move all terms containing x to the left, all other terms to the right.
Add '-2' to each side of the equation.
2 + -2 + -3x = 0 + -2
Combine like terms: 2 + -2 = 0
0 + -3x = 0 + -2
-3x = 0 + -2
Combine like terms: 0 + -2 = -2
-3x = -2
Divide each side by '-3'.
x = 0.6666666667
Simplifying
x = 0.6666666667
Subproblem 2
Set the factor '(4 + 5x)' equal to zero and attempt to solve:
Simplifying
4 + 5x = 0
Solving
4 + 5x = 0
Move all terms containing x to the left, all other terms to the right.
Add '-4' to each side of the equation.
4 + -4 + 5x = 0 + -4
Combine like terms: 4 + -4 = 0
0 + 5x = 0 + -4
5x = 0 + -4
Combine like terms: 0 + -4 = -4
5x = -4
Divide each side by '5'.
x = -0.8
Simplifying
x = -0.8
Solutionx = {0.6666666667, -0.8}</span>
Answer:
see explanation
Step-by-step explanation:
Her error is in squaring (2y)²
She has (2y)² = 2y²
when it should be 2y × 2y = 4y²
Then
(2y)² = 6² + 8²
4y² = 36 + 64
4y² = 100 ( divide both sides by 4 )
y² = 25 ( take square root of both sides )
y =
= 5