Answer:
x= -2-√11. or. x= -2 + √11
Step-by-step explanation:
solving quadratic equation by completing the square
x^2+4x-7=0
x^2+4x=7
x^2+4x + (4/2)^2=7 + (4/2)^2 ( adding (1/2 coefficient of x)^2 on both sides
x^2+4x + 4=7 + 4
x^2+4x + 4=11. factorize(x^2+4x + 4) into (x + 2)^2
(x + 2)^2=11
√(x + 2)^2= + - √11
x + 2 = + - √11
there are two different solution .
x + 2 = -√11. or x + 2 = + √11.
x= -2-√11. or. x= -2 + √11.
Well brake 7 into 5 and 2 and then just multiply it by 3 so it would be 5 x3=15 and 2x3=6 then u add 15+6 it would be the sum, of 21 so 3x7=21
(6b + 42)(b - 3)
To check the answer, use the method FOIL.
Since the 7 is in front of the parentheses you must multiply it by everything inside the parentheses. 7 times X is 7X and 7 times -2 is -14. Then you need to make the X be by itself on one side, to do that you have to add 14 to -14 to make it disappear, and also add 14 to the other side, to 28. Then you divide both sides by 7 to make X be by itself.
7(x-2)=28
7X-14=28
7x=42
X=6