LevB4Lev 2 years ago (4x+1)^2=20 solve each equation by the square root property

1. hartnn

did you take square root on both sides, first ? what you get ?

2. LevB4Lev

solve for X i mean

3. hartnn

yeah, take square root on both sides of $$(4x+1)^2=20$$ what do you get ?

4. LevB4Lev

not sure

5. LevB4Lev

4x-1=$\sqrt{20}$ =

6. hartnn

that would be $$4x+1 =\pm \sqrt {20}$$ ok? now subtract 1 from both sides, what u get ?

7. LevB4Lev

4x=$\pm \sqrt{20}$ - 1

8. hartnn

thats correct, now just divide both sides by 4 and you get 2 values of x.

9. LevB4Lev

i got x = PM square root 4

10. hartnn

? how ? $$4x=\pm \sqrt{20}-1 \implies x = \dfrac{\pm \sqrt{20}-1}{4}$$

11. LevB4Lev

|dw:1358934890536:dw|

12. LevB4Lev

so is it 19 divided by 4

13. hartnn

no, it'll only be $$x = \dfrac{\pm \sqrt{20}-1}{4}$$ or one simplification will be $$x = \dfrac{\pm 2\sqrt{5}-1}{4}$$

14. LevB4Lev

interesting