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 would make a tree because there are not that many possibilities. to get 99 with numbers between 1 and 50 you have 50+49 and 49 and 50 nothing else will work because if one spin is less than 49 say 48 to get 99 you need 51 which is impossible. either you 50 then 49 or you get 49 then 50. the others are a bit harder because you need to find all possible spins that will sum to 52 which is a much larger number.
Answer:
(-3 ,-4)
I have made it in above picture
hope it helps
Answer:
<em>I earned $856 on the first day</em>
Step-by-step explanation:
Let's call
x = earning on the second day
2x = earnings on the first day
3x = earnings on the third day
The total earnings are $2568, thus
x + 2x + 3x = 2568
Simplifying:
6x = 2568
Dividing by 6:
x = 2568/6
x = 428
I earned $428 on the second day.
2x = 2*$428 = $856
I earned $856 on the first day
