VW = VC + CW
61 = z + 13 + z + 8 = 2z + 21
2z = 61 - 21 = 40
z = 40/2 = 20
z = 20.
<span>Solve this by substitution:
</span>Solve 5x - 4y = -13 for x:<span><span><span><span>5x </span>− <span>4y </span></span>+ <span>4y </span></span>= -<span>13 + <span>4y </span></span></span>(Add 4y to both sides)
<span><span><u>5x </u></span>= <span><span><u>4y - </u><u>13 </u></span><u> </u> </span></span>(Divide both sides by 5)
5 5
<span>x = <span><span><span><u>4</u></span> y </span>+ -<span><u>13</u><span>
</span></span></span></span> 5 5
You can use https://www.mathpapa.com/algebra-calculator.html
5x - 4y = -13, 8x +10y = 12 (enter both equations with a comma between them and it will solve for you and show you step by step.
x is less than or equal to 6, because 36 is the perimeter maximum. 36/6 sides of a hexagon=6, 30/6=5, 25/6=4 and so on.