<span>2x squared - 5
= 2(x)^2 - 5
= 2(4)^2 - 5
= 2(16) - 5
= 32 - 5
= 27</span>
It would be 14.6 because the 13 in the number are below 5 so you round down
Hello again,
"katie deleted your answer to the question Hello,a=2, b=8, c=-1Indeed,y=f(x)=ax...
You've been warned"
Answer is a=2, b=8 and c=-1
Indeed:
y=f(x)=ax²+bx+c
Since (-2,-9) is the vertex,
y=k*(x+2)²-9
Or f(-1)=-7 ==> -7=k*(-1+2)²-9 ==> k=2
f(x)=2(x+2)²-9=2*(x²+4x+4)-9=2x²+8x+8-9
<u>f(x)=2x²+8x-1</u>
A proof: the picture is following.
Use your fingers.
Hold down the first finger on your left hand, nine fingers remain up. The answer is 9
For two hold down the second finger on your left hand. On the left is one finger standing, and on the right are 8 fingers standing. The answer is 18
This pattern works for everything up to ten. Then you remember 9 x 11 is 99. And 9 x 12 is 108