Answer:
x = 1, x = -19
Step-by-step explanation:
1) factorise
(x−1)(x+19)=0
2) equal to 0
x−1=0 or x+19=0
x=1 or x=−19
Answer:
[tex]x = 1[/tex]
[tex]x = 19[/tex]
Step-by-step explanation:
Set up equation
[tex] {x}^{2} + 18x - 19 = 0[/tex]
Add 19 on both sides
[tex] {x}^{2} + 18x = 19[/tex]
Divide 18 by 2 and sqr it.
[tex]( \frac{18}{2}) {}^{2} [/tex]
[tex] {9}^{2} = 81[/tex]
Add 81 on both sides
[tex] {x}^{2} + 18x + 81 = 100[/tex]
Using the AC method, isolate the left side into a binomial.
[tex](x + a)(x + b)[/tex]
that a and b can be added to equal 18 and be multiplied to equal 81.
Only number that does that is 9. 9+9=18, 9×9=81
[tex](x + 9)(x + 9)[/tex]
[tex](x + 9) {}^{2} [/tex]
Set up equation
[tex](x + 9) {}^{2} = 100[/tex]
Take sqr root of both sides
[tex]x + 9 = 10[/tex]
Since sqr root of a positve number can be negative, set up this equation also
[tex]x - 9 = 10[/tex]
[tex]x = 1[/tex]
OR
[tex]x = 19[/tex]
