Question

evaluate 2(3x-y) when a)x=10 y=-3 b)x=-3 y=10 c)x=-3 y=-10

Answer 1

@Austin1617

Answer 2

first do 3*x
when x=10 what is 3*x ?

Answer 3

should the first one look like this 2(3+10+3)=66

Answer 4

30

Answer 5

so now you have
2*(30-y)

now do 30 - y when y is -3
30 - (-3) is what ?

Answer 6

is it -33

Answer 7

two minuses make a plus
30 - -3 is the same as 30+3

Answer 8

oh 33*2 right?

Answer 9

yes

Answer 10

66

Answer 11

thank u

Answer 12

yes.

do you get the general idea?

for the next problem
b)x=-3 y=10

we can swap in those numbers into
2(3x-y) to get
2*(3*-3 - 10)

Answer 13

I put in the * to show multiplication
because we know 3x means 3*x
but if we put in -3 for x without the multiply sign: 3-3, that is wrong
we really would want 3* -3 which is -9

Answer 14

-38?

Answer 15

yes

Answer 16

thanks

Answer 17

would c look like this 2(-9+10=2

Answer 18

yes, for c) you get 2*1= 2

Answer 19

thanks