Question

10. For y = 4x + 2x2 – x3, show how to find the value for y, when x = 2. Show your work


Can some one explain how to solve this question with out giving me the answer please.

Answer 1

replace the value where the x is on the equation

Answer 2

y = 4(2) + 2x2 – (2)3

Answer 3

Remember pemdas though which means that you have to do multiplication before adding and subtracting

Answer 4

y=4(2)+2x2
4x2=8
2x2=4
Is that right

Answer 5

yes then you do the adding and subtracting

Answer 6

So do i add the 8 & 4 together

Answer 7

yup then subtract by what?

Answer 8

x^3

Answer 9

8+4=12

Answer 10

yes and its not x to the power of three but rather x times three

Answer 11

so i take away 12 from x

Answer 12

no because if you remember pemdas that stands for parenthesis, exponents, multiplication,devision, add subtract so you must do thing in an equation in that order so instead of taking 12 from x you would times x by three and then subtract 12 by that number to give you your answer

Answer 13

oh ok

Answer 14

so it would be 12-3=9

Answer 15

no you have to multiply 3 time x or 2 in this equation so what is 3x2

Answer 16

6

Answer 17

yup so what is 12-6?

Answer 18

6

Answer 19

so what is Y then?

Answer 20

6

Answer 21

exactly that is right

Answer 22

so thats all i do right

Answer 23

yup just remember pemdas and substitute the numer they give you for the variable or letter and do it in order to find the answer

Answer 24

oh ok ty