Question

what is 3(5z-7) -2(9z-11) = 4(8z-13) -17, z=? ​

Answer 1

Answer:

z=2

Step-by-step explanation:

3(5z-7)-2(9z-11)=4(8z-13)-17

=>15z-21-18z+22=32z-52-17

=>-3z+1=32z-69

=>1+69=32z+3z

=>70=35z

=>35z=70

=>z=70/35

=>z=2

Answer 2

Answer:

x-2y+3z=7

2x+y+z=4

-3x+2y-2z=-10

I changed the first equation to be able to subtract the x's:

2x-4y+6z=14

2x+y+z=4

and I got: -5y+5z=10

Then I changed the first equation again to add it to the third:

3x-6y+9z=21

-3x+2y-2z=-10

and I got: -4y +7z=11

so I changed the y's to 20 so I could subtract them:

-20y+20z=40

-20+35z=55

and I got 55z=95

which is awkward because the back of my book says that the answer to z=1.

Step-by-step explanation:

make me brainiest and thank for my answer