7 Find the exact solutions No nonterminating decimals 8 Solv
7.) Find the exact solutions. No non-terminating decimals.
8.) Solve the equation
Solution
1/5 x^2 - 3/2 x = 4/10
multiplying entire equation by 10
2x^2 - 15x = 4
subtracting 4 from both sides
2x^2 -15x - 4 = 0
solving the quadratic equation for x
x = { -b + - sqrt ( b^2 - 4ac ) } / 2a
plugging the values
x = { 15 + - sqrt ( 225 - 4(2 *-4) } / 4
x = {15 +- sqrt ( 257 ) } / 4
x = -.258 , x = 7.758
8) 4 = x + sqrt ( 4x - 19 )
subtracting x from both sides
4 - x = sqrt ( 4x - 19 )
squaring both sides to get rid of square root
( 4-x)^2 = 4x - 19
16 + x^2 - 8x = 4x - 19
x^2 -12 x + 35 = 0
solving the equation for x
( x- 7 ) ( x- 5 ) = 0
x = 7 , x = 5
by plugging each solution the equation is not verified
hence , there are no solutions for this equation
