Question

How do you solve y+2x=5 and 2x2−3x−y=16?

Answer 1

Hi there !!

y+2x=5 ---------(1)

2x² -3x-y=16 ---------(2)

We can do this by substitution method.

From equation 1

y= 5-2x -------(3)

Put y in (2)

2x²-3x-(5-2x)=16

2x²-3x-5+2x=16

2x²-x=16+5 = 2x^2-x=21

2x²-x-21=0 {Spitting the middle term)

2x²+6x-7x-21=0

2x(x+3)-7(x+3)=0

x=-3 and x= 7/2 (Ignoring -ve value)

Put the value of x in equation (3)

y= 5- 2×7/2

y=5-7=-2

Hence, x = 7/2 and y= -2

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Thankyou :)