Answer:
Step-by-step explanation:
y=x²-2x-1
and y=-3x+5
x²-2x-1=-3x+5
x²+x-6=0
x²+3x-2x-6=0
x(x+3)-2(x+3)=0
(x+3)(x-2)=0
x=-3,2
when x=-3
y=-3×-3+5=9+5=14
when x=2
y=-3×2+5=-6+5=-1
so solutions are (-3,14) and (2,-1)
The ball will hit the ground between 8 and 9 seconds
Answer:
8 and 6
Step-by-step explanation:
If you use x for the first number, and y for the second, you get equations of 3x+5y=54 and x-2=y.
You can substitute the second equation into the first one to solve it. This gives 3x+5(x-2)=54.
The brackets can be expanded to 3x+5x-10=54. Collecting like terms makes it 8x-10=54.
Next, we add 10 to both sides. This gives 8x=64.
From there, we isolate the x by dividing both sides by 8, giving x=8.
To work out the second number, we can sub 8 for x in either equation (I'm using the second one as it's simpler).
This comes to y=8-2, therefore y=6.
**This content is simultaneous equations, which you may wish to revise. I'm always happy to help!
Answer:
4.68
Step-by-step explanation:
Remember to line up the decimal point. Subtract as ordinarily.
8.31
-3.43
--------
4.68
4.68 is your answer
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