Solve the simultaneous equations. x^2 + 2y=9, y-x=3
Use the method of substitution to answer this question.
Step 1: Rearrange one of the equations to find x or y.
y-x=3 y=x+3
Step 2: Substitute your y into the first equation
x2+2y=9 x2+2(x+3)=9
Step 3: Expand the brackets and rearrange to form a quadratic equation
x2+2x+6=9 x2+2x-3=0
Step 4: Factorise the equation to find your values for x
(x+3)(x-1)=0Therefore x=-3 or x=1
Step 5: Find the corresponding y values
y=x+3when x=-3 y=0 and when x=1 y=4
KW
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