These questions are pertaining to College Algebra

Question

1) a^2 + b^2 = c^2, solve for b

 

2) Solve each equation: 3x^4 + 10x^2 - 25 = 0

(x+200)^2/3 = 36

 

(x-3)^2/5 = (4x)^1/5

 

3) Solve each equation:     7       +       19       = 6                    

                                      x^2               x

Answer 1

1) b = sqr(c^2 - a^2)

2) 3x^4 +10x^2 -25 = 0

let y=x^2

3y^2+10y-25 =0

(3y-5)(y+5)=0

y=-5, or 5/3

x^2 =-5 or 5/3

x = +-isqr5 or +/-sqr(5/3)

(x+200)^(2/3) = 36

x+200 = 36^(3/2) = 216

x = 16

(x-3)^(2/5) = (4x)^(1/5)

graph it x= 1 or 9

3) 7/x^2 + 19/x = 6

multiply by x^2

6x^2 = 19x +7

6x^2 -19x -7 = 0

x = 19/12 + or - (1/12)sqr(19^2 +4(6)(7))

= (19+ or -23)/12 = 42/12 or -4/12 = -1/3 or 3.5

graph it, x intercepts = about 3.5 and - 1/3