Question

The factorisation of 84 - 2r - 2r²,is​

Answer 1

Given,

84-2r-2r²

Multiply by -1,

2r²+2r-84

Divide by 2,

r²+r-42

r²+7r-6r-42

r(r+7)-6(r+7)

(r-6)(r+7)

Answer 2

Answer:

84-2r-2r²=0

-2r²-2r-84=0

-2(r²-r-42)=0

r²-r-42=0/-2

r²-7r+6r-42=0

r(r-7)+6(r-7)=0

(r-7)(r+6)=0

r-7=0

r=7

r+6=0

r=-6

I hope it will help you.

Step-by-step explanation:

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