Question

Please solve the system of equations!

Answer 1

`\bold{\huge{\red{\underline{ Solution}}}}`

`\bold{\underline{ We \: have\: given :-}}`

`\sf{ 7x - 3y = 20. ...eq(1 ) }`

`\sf{ y = 5x - 4. ...eq(2) }`

Here, we will use the substitution method for solving the above equations.

`\bold{\underline{Subsitute \: eq(1)\:in \: eq(2)}}`

`\sf{ 7x - 3(5x - 4) = 20 }`

`\sf{ 7x - 15x + 12 = 20}`

`\sf{ - 8x + 12 = 20 }`

`\sf{ - 8x = 20 - 12 }`

`\sf{ - 8x = 8}`

`\sf{ x = 8/-8}`

`\sf{ x = - 1. ...eq( 3 )}`

`\bold{\underline{Subsitute \: eq(3)\:in \: eq(2)}}`

`\sf{ y = 5(-1) - 4 }`

`\sf{ y = - 5 - 4 }`

`\sf{ y = - 9 }`

`\sf{\blue{ Hence, \: The \:value \:of \:x \:and \:y \:is\: - 1 \: and \:-9}}`