Question 999897
Let the cost of the microwave be M. Let the cost of the TV be T

You are told
{{{T = 4M -7}}}

You are also told
{{{T + M = 438}}}

{{{(4M-7) + M = 438}}}
{{{5M - 7 = 438}}}
{{{5M = 445}}}
{{{M = 89}}}

So the TV is {{{(4*89) - 7}}} = 349

So the two items total to 438??