Question

What is the value of the positive zero of the function defined by 15x2 + 100x – 70 – (17x – 6x2)?

A.
eq115910_a1

B.
eq115910_b1

C.
eq115910_c1

D.
eq115910_d1

Answer 1

hello

15 x² + 100 x - 70 - 17 x + 6 x²

= 9 x² + 83 x - 70

9 x² + 83 x - 70 = 0

Δ = 83 ² - 4 ( 9 * - 70 ) = 6 889 + 2 520 = 9 409 = 97 ²

x 1 = ( - 83 - 97 ) / 18 = - 180/18 = - 10

x 2 = ( - 83 + 97 ) / 18 = 14 /18 = 7 /9

Explanation: