Question

3. Find the value of the following expressions, when x=-1:
(i) 2x - 7
(ii) - x + 2
(iii) x²+2x +1
(v) 2x²-x-2​

Answer 1

Step-by-step explanation:

when x=-1

i)2x-7=2×(-1)-7= -2-7= -9

ii) -x+2= -(-1)+2=3

iii)x^2+2x+1=(-1)^2+2×(-1)+1=1-2+1=0

iv)2x^2-x-2=2(-1)^2-(-1)-2=2+1-2= 1

Answer 2

Step by step explanation:

x = -1

(I) 2x -7

= 2 (-1) - 7

= -2 - 7

= -9

(ii) -x +2

= -(-1) +2

= 1 + 2

= 3

(iii) x^2 + 2x + 1

= (-1) ^2 + 2(-1)+1

= 1 - 2 +1

= 2 - 2

= 0

(iv) 2x^2 -x -2

= 2(-1)^2 -(-1)-2

= 2(1) +1-2

= 2 +1 -2

= 3 -2

= 1