Question

Solve the system, 7x-9y=29 7x+2y=-15

Answer 1

`\begin{gathered} \text{This's is a simualtaneous equation.} \\ 7x\text{ - 9y = 29}----------(1) \\ 7x\text{ + 2y = 15}----------(2) \\ \text{subtracting equation (2) from equation (1) becomes} \\ 7x\text{ - 9y = 29}----------(1) \\ -(7x\text{ + 2y = 15)}----------(2) \\ -11y\text{ = 29-15} \\ -11y\text{ = 14} \\ y\text{ = }(14)/(-11)\text{ = } \\ \text{substitute y into equation(1) so as to get x} \\ 7x\text{ - 9(}(14)/(-11)\text{) = 29} \\ 7x\text{ + }(126)/(11)\text{ = 29} \\ 7x\text{ = 29 - }(126)/(11) \\ 7x\text{ = 29 - 11.45} \\ 7x\text{ = 17,54} \\ x\text{ = }(17.54)/(7)\text{ = 2.506} \end{gathered}`