Step 1: First rearrange second equation for either x or y (in this example it is easier to make y the subject of the equation: y = 13+3xStep 2: Substitute the expression obtained for y into the first equation ( (x^2) + (13+3x)^2 = 25 )Step 3: Clean up the equation ( 10x^2+78x+144 = 0 )Step 4: Factorise ( (5x+24) (x+3) = 0 )Step 5: Solve for x ( x = -24/5 and -3 )Step 6: Substitute calculated values of x into the first rearranged equation of y to obtain corresponding values of y ( y = -7/5 and 4 )