Solve the following equations and check the answers :
Question 1 :
√x = 5√2
Question 2 :
√-y = 3√7
Question 3 :
√(3x + 12) = 3√3
Question 4 :
√(x - 5) = 2√6
Question 5 :
√(3x - 4) = √6
Question 6 :
√(x2 - 2) = √(x + 4)
Question 7 :
√(x - 6) = √(x + 9) - 3
Question 8 :
3√(x - 6) = 3√(2x - 9)
1. Answer :
√x = 5√2
Square both sides.
(√x)2 = (5√2)2
x = 52√22
x = 25(2)
x = 50
Check Answer :
√50 = 5√2 ?
√(5 ⋅ 5 ⋅ 2) = 5√2 ?
5√2 = 5√2 ✓
Therefore, the solution is
x = 50
2. Answer :
√-y = 3√7
Square both sides.
(√-y)2 = (3√7)2
-y = 32√72
-y = 9(7)
-y = 63
Multiply both sides by -1.
y = -63
Check Answer :
√[-(-63)] = 3√7 ?
√63 = 3√7 ?
√(3 ⋅ 3 ⋅ 7) = 3√7 ?
3√7 = 3√7 ✓
Therefore, the solution is
y = -63
3. Answer :
√(3x + 12) = 3√3
Square both sides.
[√3x + 12)]2 = (3√3)2
3x + 12 = 32√32
3x + 12 = 9(3)
3x + 12 = 27
Subtract 12 from both sides.
3x = 15
Divide both sides by 3.
x = 5
Check Answer :
√(3(5) + 12) = 3√3 ?
√(15 + 12) = 3√3 ?
√27 = 3√3 ?
√(3 ⋅ 3 ⋅ 3) = 3√3 ?
3√2 = 3√3 ✓
Therefore, the solution is
x = 5
4. Answer :
√(x - 5) = 2√6
Square both sides.
[√(x - 5)]2 = (2√6)2
x - 5 = 22√62
x - 5 = 4(6)
x - 5 = 24
Add 5 to both sides.
x = 29
Check Answer :
√(29 - 5) = 2√6 ?
√24 = 2√6 ?
√(2 ⋅ 2 ⋅ 2 ⋅ 3) = 2√6 ?
2√(2 ⋅ 3) = 2√6 ?
2√6 = 2√6 ✓
Therefore, the solution is
x = 29
5. Answer :
√(3x - 4) = √6
Square both sides.
[(√(3x - 4)]2 = (√6)2
3x - 4 = √62
3x - 4 = 6
Add 4 to both sides.
3x = 6 + 4
3x = 10
Divide both sides by 3.
x = 10/3
Check Answer :
√(3(10/3) - 4) = √6 ?
√(10 - 4) = √6 ?
√6 = √6 ✓
Therefore, the solution is
x = 10/3
6. Answer :
√(x2 - 2) = √(x + 4)
Square both sides.
[√(x2 - 2)]2 = [√(x + 4)]2
x2 - 2 = x + 4
Subtract x and 4 from both sides.
x2 - x - 6 = 0
Solve by factoring.
(x + 2)(x - 3) = 0
x + 2 = 0 x = -2 |
x - 3 = 0 x = 3 |
Check Answers :
x = -2 : √((-2)2 - 2) = √(-2 + 4) ? √(4 - 2) = √2 ? √2 = √2 ✓ |
x = 3 : √(32 - 2) = √(3 + 4) ? √(9 - 2) = √7 ? √7 = √7 ✓ |
Therefore, the solutions are
x = -2 and x = 3
7. Answer :
√(x - 6) = √(x + 9) - 3
Square both sides.
[√(x - 6)]2 = [√(x + 9) - 3]2
x - 6 = [√(x + 9) - 3][√(x + 9) - 3]
x - 6 = [√(x + 9)]2 - 3√(x + 9) - 3√(x + 9) + 32
x - 6 = x + 9 - 6√(x + 9) + 9
x - 6 = x - 6√(x + 9) + 18
Subtract x from both sides.
-6 = -6√(x + 9) + 18
Subtract 18 from both sides.
-24 = -6√(x + 9)
Square both sides.
(-24)2 = [-6√(x + 9)]2
576 = (-6)2[√(x + 9)]2
576 = 36(x + 9)
Divide both sides by 576.
16 = x + 9
Subtract 9 from both sides.
7 = x
Check Answer :
√(7 - 6) = √(7 + 9) - 3 ?
√1 = √16 - 3 ?
1 = 4 - 3 ?
1 = 1 ✓
Therefore, the solution is
x = 7
8. Answer :
3√(x - 6) = 3√(2x - 9)
Raise both sides to the 3rd power.
[3√(x - 6)]3 = [3√(2x - 9)]3
x - 6 = 2x - 9
Subtract x from both sides.
-6 = x - 9
Add 9 to both sides.
3 = x
Check Answer :
3√(3 - 6) = 3√(2(3) - 9) ?
3√(-3) = 3√(6 - 9) ?
3√(-3) = 3√(-3) ✓
Therefore, the solution is
x = 3
Kindly mail your feedback to v4formath@gmail.com
We always appreciate your feedback.
©All rights reserved. onlinemath4all.com
Dec 26, 24 07:41 AM
Dec 23, 24 03:47 AM
Dec 23, 24 03:40 AM