Question

4. If ∆ = 3/8x - 4x² + 6, [] = x² - 5x + 5/8 and
$ = -x² + 7/8x - 12, then find the value of :-

I) 2∆ - [] + 1/2$

II) ∆ + [] - 2$

explain your answer.

Inappropriate answers like " I don't know " will be reported​​

Answer 1

Answer:

4)

I ) -19/2x² + 99/16x +43/8

II ) -x² -51/8x + 245/8

Step-by-step explanation:

Ans 4)

(I)

2∆ - [] + 1/2$

= 2( 3/8x - 4x² + 6) -(x² - 5x + 5/8) +1/2(-x² + 7/8x - 12)

= 3/4x-8x²+12 -x² +5x -5/8 -1/2x² +7/16x - 6

Rearranging terms

= (-8x²-x²+1/2x² ) + (3/4x +5x+7/16x ) + (12-5/8-6)

= (-9-1/2)x² +(5+19/16)x + (6-5/8)

= -19/2x² + 99/16x +43/8

(II) ∆ + [] - 2$

= 3/8x - 4x² + 6 + x² - 5x + 5/8 -2(-x² + 7/8x - 12)

= 3/8x - 4x² + 6 + x² - 5x + 5/8 +2x² -7/4x +24

Rearranging terms

=( -4x² +x² +2x²) + (3/8x-5x -7/4x) +(6+5/8+24)

= -x² -51/8x + 245/8