Answer:
x = 2±sqrt(11)
Step-by-step explanation:
x^2 -4x - 7 =0
Add 7 to each side
x^2 -4x -7+7 =0+7
x^2 -4x =7
To complete the square take the coefficient of the x term and divide by 2 and then square it. Add it to both sides
-4 /2 = -2 then square
(-2)^2 = 4
Add 4 to both sides
x^2 -4x+4 =7+4
x^2 -4x+4 = 11
Factor the left side into (x-b/2)^2
(x-2)^2 =11
Take the square root of each side
sqrt((x-2)^2) =±sqrt(11)
x-2 = ±sqrt(11)
Add to to each side
x-2+2 = 2±sqrt(11)
x = 2±sqrt(11)
Answer:
Step-by-step explanation:
-5 x 5 = -25
5x+4y = 73
-4x + 4y = -8
5x + 4y -(-4x+4y) = 73 -(-8)
5x + 4y + 4x - 4y = 81
5x + 4x + 4y - 4y = 81
9x = 81
x = 81÷9
x = 9
Substitute x = 9 into any of the equations to find y.
5(9) + 4y = 73
45 + 4y = 73
4y = 73 - 45
4y = 28
y = 28÷4
y=7
Answers :
x = 9
y = 7
Answer: y3=x y 3 = x
Step-by-step explanation:
