11. You’ve done it correctly
12. Let x^2=y
y^2+13y+40=0
(y+8)(y+5)=0
y=8, 5
Since y=x^2
x^2=8 x^2=5
x=+/-√5 x= +/-2√2
13. x^4-x^2-x^2-8=0
x^4-2x^2-8=0
let x^2=y
Y^2-2y-8=0
(y-4)(y+2)=0
y=4, -2
Since y=x^2
X^2=4 X^2=-2
X= +/- 2 This wouldn’t be a real solution
14. It’s pretty much the same process, just substitute y in for x^2. If you’re confused feel free to ask and I can do it, or you can put it through Photomath
15. You’re on the right track so I’m just going to continue from where you left off
x^2(4x+5)-4(x+5)=0
(x^2-4)(4x+5)=0
x= +/- 2 4x=5
x=5/4 or 1 1/4
Hope this helped :)
I believe the answer is about 78.81% because you subtract 25 from 118. Then that would be 93. 118 is equal to the 100% and 118 divide by 1.18 equals 100. Divide 93 from 1.18 gives you the answer
Answer:
5.02655
Step-by-step explanation:
Answer:
w = 4
Step-by-step explanation:
you would do this by re-arranging the equation
6 = 5w-10-w (move w to the other side)
6 = 4w-10 (because 5w-w = 4w)
6+10=4w (move 10 to the other side)
16 = 4w (add 6 and 10)
4 = w (divide both sides by 4)
Answer:

Step-by-step explanation:
To factor an expression you have to first find the highest common factor (HCF) of the numbers in the expression. You divide them by their HCF, bracket it and place the HCF outside the bracket.

To check if it is factored properly you can do the opposite of what you just did by clearing the bracket.
9 (7 + 9)
(9 x 7) + (9 x 9)
= 63 + 81