Chapter 4 Quadratic Functions and Factoring - 4.10 Write Quadratic Functions and Models - 4.10 Exercises - Mixed Review - Page 315: 61

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Given: $3x+4y=-1\\2x+6y=-31$ Multiply the second equation by $2$: $6x+8y=-2$ Multiply the second equation by $-3$ $-6x-18y=93$ Then add the new equations $-10y=91\\ \rightarrow y=-\frac{91}{10}$ Substitute: $3x+4(-\frac{91}{10})=-1\\ \rightarrow 3x=\frac{354}{10}\\ \rightarrow x=\frac{59}{5}$