Question

how do i solve this √2x -7+8=11

Answer 1

if the whole (2x-7+8) under square root then we get rid of sqr rt from both sides:

2x-7+8=(11)^2
2x+1=121
2x=120
x=60

if only (2x) is under square root, then:
ã2x +1=11
ã2x =10
2x=(10)^2
2x=100
x=50

Answer 2

If you mean
√(2x - 7) + 8 = 11
Then, first we isolate the whole squareroot term on one side of equation:
√(2x - 7) = 11 - 8
√(2x - 7) = 3
Then we square both sides:
2x - 7 = 9
2x = 9 + 7
2x = 16
x = 8
Note that if we're dealing with squareroots, we always check whether the answer can satisfy the original equation, or it is extraneous. Substituting x = 8,
√(2x - 7) + 8 = 11
√(2*8 - 7) + 8 = 11
√(16 - 7) + 8 = 11
√(9) + 8 = 11
3 + 8 = 11
11 = 11
Thus x is equal to 8.

Hope this helps~ :3