3x + 4y + 7z = 12. x=2 and y=-1, what is the value of z to 2 dp?
first you sub in the values you know so3(2) + 4(-1) + 7z =12then you simply the equation6-4+7z=122+7z=12then you put all the letter values on one side and all the numbers on the other12-2= 7zthen simplify10=7zthen put all the letter values on one side and all the numbers on the other again10/7=zthen solve for zz=1.43 (to 2dp)
EP
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