Answer:
3
Explanation:
step1 Isolate the square root on the left hand side
Original equation
√2x-5-4 = -x
Isolate
√2x-5 = 4-x
step2 eliminate the radical on the left hand side
Raise both sides to the second power
(√2x-5)2 = (4-x)2
After squaring
2x-5 = x2-8x+16
step3 Solve the quadratic equation
Rearranged equation
x2 - 10x + 21 = 0
This equation has two rational roots:
{x1, x2}={7, 3}
step4 Check that the first solution is correct
Original equation, root isolated
√2x-5 = 4-x
Plug in 7 for x
√2•(7)-5 = 4-(7)
Simplify
√9 = -3
Solution does not check
3 ≠ -3
step5 Check that the second solution is correct
Original equation, root isolated
√2x-5 = 4-x
Plug in 3 for x
√2•(3)-5 = 4-(3)
Simplify
√1 = 1
Solution checks !!
Solution is:
x = 3