Math problem question?

Question

Given f(x)=3x^2-4x, determine f(-5)? Do i just input -5 in the x spots?

Answer 1

Your idea is right .You can answer and get the answer...

But i will give the answer to you..

f(x) = 3x^2 - 4x ;f(-5)

f(-5) = 3(-5)^2 - 4(-5)

f(-5) = 3(25) - 20

f(-5) = 75 - 20

f(-5) = 55

Answer 2

yes! that's 3(-5)^2  -4(-5) = 75 + 20 = 95.

anyway, you have a question which has been deleted by the community, her's the answer.

1.to find the slope, change the equation into a form of y = mx+ b. the slope is m, which is -2/5.

2. get the slope using those points. the slope is (19-15)/(6-4) = 4/2 = 2. the y- intercept is taken by computing for b using any of the two points. the y-intercept is 7. the equation is y = 2x + 7.

3. the domain are simply the first numbers in each pair, the range are the last numbers. that's a function.

4. substitute -5 in the function, that's 3(-5)^2 -4(-5) = 75 + 20 = 95.

5. x^2 -4x -21

6. x^2 - 10x +25

7. 5x^2 -2x - 8