Solve:

x2 + y2 = 25 y – 3x = 13 Rearrange the second equation: y = 13 + 3x Substitute the rearranged question in the first equation: x2 + (13 + 3x)2 = 25 Solve: x2 + 169 + 9x2 + 78x - 25 = 0 10x2 + 78x + 144 = 0 5x2 + 39x + 72 = 0 x = (-39 +- /1521-1440)/10 x = (-39 +-9)/10 x = -4.8, x = -3 Subsitute these two values in the rearranged equation: x = -4.8 --> y = 13 + 3*(-4.8) = -1.4 x = -3 --> y = 13 + 3*(-3) = 4

BJ

Related Maths GCSE answers

All answers ▸

For all values of x f(x) = x^2 + 2 g(x)= x - 5 show that fg(x) = x^2 -10x +27


How do I rationalise the denominator? (Surds)


GCSE Maths: Expand and simpify 14(3x-7y)-2x(21-y)


Factorise 4x + 52