Solve these two simultaneous equations.
eq.1 4x+3y=7eq.2 3x+7y=16
You want to eliminate one of the variables (either x or y) reducing the problem to just one equation with one variable which can be solved. This can be done by multiplying each equation by a factor and then subtracting one equation from the other. In this case, eliminating x.
Multiplying eq1. by 3 gives: eq.3 12x+9y=21eq.2 by 4 gives: eq.4 12x+28y=64Then subtracting eq.3 from eq.4 (to give a positive multiple of y, although the opposite calculation could be done) leaves: 19y=43 therefore y=43/19. Subbing this number back into either of the original equations solves for x. A check can be performed by subbing both obtained values into the other equation and ensuring the answer is consistent.
TH
Related Maths GCSE answers
All answers ▸Each day Chen buys pasta or a sandwich. Where Pasta costs £3.20 and Sandwich costs £2.75. For 45 days, the relative frequency of Chen buying a sandwich was one fifth. Altogether, how much did he pay?
solve to 2 decimal places; (2x+3/(x-4)) - 2x-8/(2x+1) = 1
Tom is making gift bags, each of which will contain two balloons. He wants to hide a sweet in one of the balloons. 20 balloons cost £1.33, 15 sweets cost £2.05. What is the minimum he needs to spend to make 35 bags?
When would I use the quadratic formula?