simultaneous equations

Solve
2a + b = 3
4a - 5b = 20

My attempt
Multiply the first equation by 5
So,
10a + 5b = 15
4a - 5b = 20
Add them together
14a = 35
Divide both sides by 14
a = 2.5
Substitute (I have done it with the second one)
10 - 5b = 20
Take away 10 from both sides
5b = 10
Divide both sides by 5
b = 2

When I checked if the answers were right by fitting them back into the equation it didn't work

Please help

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asked by hs
  1. b = NEGATIVE TWO
    scroll down to your first question for my solution
    PLEASE POST ONCE

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    posted by Damon

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