Answer:

Step-by-step explanation:
Given
← factorise numerator and denominator
2x² - 18 ( factor out 2 from each term )
= 2(x² - 9) ← difference of 2 squares
= 2(x - 3)(x + 3)
and
x² + 4x - 21 = (x + 7)(x - 3) , then
=
← cancel common factor (x - 3) on numerator/ denominator
= 
Answer:
14.4 × 10^13
Step-by-step explanation:
.........
Answer:5 and -5
Step-by-step explanation:
There's not really any steps but absolute value is the number of spaces a numerical value is from 0 so 5 is 5 spaces away and -5 is also 5 spaces away -3 is 3 spaces away and 8 is 8 spaces away.
<span>x= -8 + y
-9x + 6y= 9
substitute </span>x= -8 + y into -9x + 6y= 9
-9x + 6y= 9
-9(-8 + y) + 6y= 9
72 - 9y + 6y = 9
-3y = -63
y = 21
<span>x= -8 + y
</span><span>x= -8 + 21
x = 13
solution (13, 21)</span>