Question 697884
Equation 1:{{{A = 2B}}}
Equation 2:{{{B = 4C}}}
Equation 3:{{{(A+B+C)/3 = 39}}}
Since B = 4C and A = 2B; A = 4C*2
So A = 8C
Rewrite equation 3 in terms of C
Equation 3:{{{(A+B+C)/3 = 39}}}
{{{(8C + 4C + C) / 3 = 39}}}
Multiply both sides by 3
{{{8C + 4C + C = 117}}}
Simplify
{{{13C = 117}}}
Divide both sides by 13
{{{highlight(C = 9)}}}
Now plug 9 into equation 2 for C
Equation 2:{{{B = 4C}}}
{{{B = 4*(9)}}}
{{{highlight_green(B = 36)}}}
Now plug 36 into equation 1 for B
Equation 1:{{{A = 2B}}}
{{{A = 2*(36)}}}
{{{highlight(A = 72)}}}