6. times both sides by 5 5a=b+c minus b both sides 5a-b=c c=5a-b 7. distribute invibile -1 2x²+5x-4-3x²-7x+1 -1x²-2x-3 -x²-2x-3

a=(b+c)/5  multiply both sides by 5 5a=b+c  subtract b from both sides c=5a-b ... 2x^2-3x^2+5x-7x-4+1 -x^2-2x-3