Q. If (x,y) is a solution to the system of equations shown, what is the product of the y-coordinates of the solutions?x2+4y2=40x+2y=8
Solve linear equation for x: Solve the linear equation for x. The linear equation is x+2y=8. We can solve for x by isolating it on one side of the equation. x=8−2y
Substitute expression for x into quadratic equation: Substitute the expression for x into the quadratic equation.The quadratic equation is x2+4y2=40. We substitute x=8−2y into this equation to get:(8−2y)2+4y2=40
Expand and simplify the equation: Expand the squared term and simplify the equation.Expanding (8−2y)2 gives us 64−32y+4y2. Now we have:64−32y+4y2+4y2=40Combine like terms to get:64−32y+8y2=40
Move all terms to one side: Move all terms to one side to set the equation to zero.Subtract 40 from both sides to get:8y2−32y+24=0
Simplify the equation by dividing all terms: Simplify the equation by dividing all terms by 8.Dividing each term by 8 gives us:y2−4y+3=0
Factor the quadratic equation: Factor the quadratic equation.The equation y2−4y+3factors into:(y−3)(y−1)=0
Solve for y: Solve for y by setting each factor equal to zero.Setting each factor equal to zero gives us two possible y-values:y−3=0 or y−1=0So, y=3 or y=1
Find the product of the y-coordinates: Find the product of the y-coordinates.The product of the y-coordinates of the solutions is:3×1=3
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