2x-3+x=12-x+1
to solve an equation like this we have to put all the variables on one side and all the numbers on the other. we do this by subtracting, adding, multiplying, or dividing by the same things on each side of the equality.
lets add 3 to both sides first. you get
2x+x=12-x+1+3
now add x on both sides
2x+x+x=12+1+3
combine the terms
4x=16
divide by 5 on each side
x=4
Replace the f(x) with y and proceed to make x the subject:
y=1/4x-12
y+12=1/4x
To ÷1/4 on both sides, ×4 on both sides
4(y+12)=x
4y+48=x
Now swap y with x and replace the isolated x with f(x) to get the inverse function:
<em>If f(1) = 1 that means c is -2 because when you substitute x = 1 and when c = -2, you'll get f(1) = -2(1)+3 = -2+3 = 1</em>
<em>So the constant c is -2 and that means the value of f(-4) is</em>
<em>f(-4)=-2(-4)+3=8+3=11</em>
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<em>Thus, the value of f(-4) is 11.</em>
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<em>About why does "c" have to be -2, here's the proof.</em>
<em>Given y = f(x), therefore.</em>
<em>y=cx+3</em>
<em>Since when x = 1 and y = 1, then Substitute x = 1 and y = 1, thus 1 = c+3</em>
<em>1 - 3 = c and therefore, -2 = c #</em>
<em>So this is the proof that c = -2</em>
Answer:
the Answer is c I just had the same problem