algebra word problem

Question

three pens and two notebooks cost $8.25. Two pens and three notebooks cost $8.00. How much would two pens and two notebooks cost

Answer 1

3P + 2N = 825

2P + 3N = 800

multiply 1st equation by 2 and 2nd equation by 3, and subtract, eliminating one variable

6P+9N = 2400

6P + 4N = 1650

5N = 750

N =750/5 = 150

2P + 3(150) = 800

2P = 800 -450 = 350

p = 350/2 = 175

2P + 2N = 2(175) + 2(150) = 350 +300 = 650 = $6.50