Why do we use simultaneous equations?
Simultaneous equations are used to help us find unknown values. An example of simultaneous equations is:1) x + y = 62) 2x + 3y = 16We don't know what the value or X or Y is but we know that together they make 6. This is the same as if you buy an apple and an orange for £6, but you don't know how much the apple or orange costs individually. Therefore, we use another equation to help us work this out. We can then rearrange equations to find the value for X and Y in turn, and therefore the cost of an individual apple or orange. rearranging (1) gives x = 6 - y which we can substitute into equation (2) to give 2(6 -y) + 3y = 1612 - 2y +3y = 1612 + y = 16 y = 4 therefore, x = 6 - 2 x = 2We have used simultaneous equations to find two unknown values!
Related Maths GCSE answers
All answers ▸Emma wants to buy a radio, the full price is £80. In the shop, she is given a discount. A year later, she sells the radio for £78, giving her a profit of 30% of what she bought it for the year before. What discount did she receive? (4)
Quadratic equation
How do you rationalise surds?
Work out the integer values that satisfy: x^2−7 x+ 11<0