solve and check equation of square root?

Question

The square root of (2y+7) +4=y

Answer 1

sqr(2y+7) +4 = y

sqr(2y+7) = y - 4

2y + 7 = y^2 - 8y + 16

0 = y^2 -10y + 9

0 = (y-1)(y-9)
y = 1 or 9

sub 1 and 9 back in to check if it works.

1 doesn't work, so 9 is the answer

Answer 2

Suggest that you use a more compact notation:
sqrt(2y+7) + 4 =y
sqrt(2y+7)= y-4
square both sides:
2y+7= y^2-8y+16
Collect terms
0=y^2-10y+9
Factor
0=(y-9)(y-1)
Thus, y=9 or 1
Check: For y=9, 2y+7=25. Then does 5+4 = 9 Yes
For y=1, 2y+7=0 . Then does 3+4 = 1 No
Dont feel bad, the initial equation has only one root. The other root is introduced when you squared the equation.
y = 9.

Answer 3

sqrt = square root.

So, sqrt{2y + 7} + 4 = y

sqrt{2y + 7} = y - 4

sqrt{2y +7}^2 = sqrt{y - 4}^2

2y + 7 = y - 4

2y - y = -4 - 7

y = -11

CHECK:

Plug y = -11 into the original equation and simplify.

The idea is to get the same answer on BOTH sides of the equation. This is what EQUAL means anyway.

sqrt{2y+7} +4 = y...ORIGINAL EQUATION

sqrt{2(-11) + 7} + 4 = -11

sqrt{-22 + 7} + 4 = -11

sqrt{-15} + 4 = -11

Do you see -15 INSIDE the square root?

We CANNOT take the square root of a negative number.

So, y = -11 is not a root or solution for this equation.

Guido

Answer 4

i assume this usual one is: sqrt(2x + 3) = 7 sq. each and each area to get rid of the sqrt: 2x + 3 = 40 9 Subtract 3 from each and each area: 2x = 40 six Divide by 2: x = 23 So, we've a answer, plug it in to study: sqrt(2(23) + 3) = 7 sqrt(40 six + 3) = 7 sqrt(40 9) = 7 7 = 7 So, our answer is sweet, and x = 23. For the subsequent, commence the following: x = sqrt(4x - 3) lower back, sq. each and each area: x^2 = 4x - 3 that is the position it differs from the finest. it really is now a quadratic, so we ought to re-manage to placed all values on an similar area: x^2 - 4x + 3 = 0 element: (x - 3) * (x - a million) = 0 subsequently, there are 2 ideas, x = a million and x = 3. Plug those in to study: a million = sqrt(4(a million) - 3) a million = sqrt(4 - 3) a million = sqrt(a million) a million = a million and three = sqrt(4(3) - 3) 3 = sqrt(12 - 3) 3 = sqrt(9) 3 = 3 So, both are appropriate, and subsequently the second one one has 2 ideas, x = a million and x = 3

Answer 5

Something is missing or you may be confused. You have an equation, not a value to find the square root of. In your equation, y= -11.

Negative numbers do not have square roots.

Answer 6

sqrt of 2y+7+4=y
sqrt of 2y+7=4-4=y-4
sqrt of 2y+7-y=y-y-4
sqrt of y+7=-4
sqrt of y+7^2=-4^2
y+7=16
y+7-7=16-7
y=9

Answer 7

(2y+7)=(y-4)^2
2y+7=y^2+16-8y
y^2-10y+9=0
Then use the cuadratic solution.