Solve the simultaneous equations: 4x+5y = 38 , x-y = 5
Firstly number the two equations 1 and 2 for simplicity. To solve this we want to eliminate one of the variables, x or y, so we start by looking at the equations and seeing if we can add or subtract them from each other to get rid of one of the variables. From these equations it doesnt look like we can do this immediately. What we do now is multiply equation two (x-y=5) by 5, to get our new equation three : 5x-5y =25. REMEMBER to multiply the right hand side as well... Now we see we can add equation three to eqaution one and this removes y...we are left with 9x =63. Divide by 9 to get x=7. Now plug x = 7 into one of the original equations, for simplicity use equation two. And this gives us y=2
AA
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