X = apples and y = oranges 3x + 2y = 9.93...multiply by 2 2x + 3y = 9.82...multiply by -3 ------------------ 6x + 4y = 19.86 (result of multiplying by 2 -6x - 9y = - 29.46 (result of multiplying by -3) -----------------add -5y = - 9.6 y = -9.6 / -5 y = 1.92 <==== cost per kg for oranges
2x + 3y = 9.82 2x + 3(1.92) = 9.82 2x + 5.76 = 9.82 2x = 9.82 - 5.76 2x = 4.06 x = 4.06/2 x = 2.03 <== cost per kg per apples ======================== P = 2(L + W) P = 30 L = 2W
30 = 2(2W + W) 30 = 2(3W) 30 = 6W 30/6 = W 5 = W <=== width is 5 cm
L = 2W L = 2(5) L = 10 <== length is 10 cm ======================= x = first number and y = second number 4x + 3y = 15....multiply by 2 3x - 2y = 7...multiply by 3 ----------------- 8x + 6y = 30 (result of multiplying by 2) 9x - 6y = 21 (result of multiplying by 3) ----------------add 17x = 51 x = 51/17 x = 3 <=== first number
3x - 2y = 7 3(3) - 2y = 7 9 - 2y = 7 -2y = 7 - 9 -2y = -2 y = -2/-2 y = 1 <=== second number ====================== x = sons age and y = fathers age 2x + y = 95 x + y = 70...multiply by -1 ------------- 2x + y = 95 -x - y = -70 (result of multiplying by -1) ------------add x = 25 <== sons age
2x + y = 95 2(25) + y = 95 50 + y = 95 y = 95 - 50 y = 45 <=== fathers age ===================== sorry but I dont know the last one...never was good at those kinds of problems
