Question

37 Subtract.
(ii) the sum of 3x2 + 2x – 1 and 2x2 + 3x - 5
from the sum of 5x2 – 2x and 3x2 - x + 3​

Answer 1

(x3 + 3x2 + 5x – 4) – (3x3 – 8x2 – 5x + 6)

(x3 + 3x2 + 5x – 4) – 1(3x3 – 8x2 – 5x + 6)

(x3 + 3x2 + 5x – 4) – 1(3x3) – 1 (–8x2) – 1(–5x) – 1(6)

x3 + 3x2 + 5x – 4 – 3x3 + 8x2 + 5x – 6

x3 – 3x3 + 3x2 + 8x2 + 5x + 5x – 4 – 6

–2x3 + 11x2 + 10x –10

And here's what the subtraction looks like, when going vertically:

\small{ \begin{array}{rrrr}x^3&+3x^2&+5x&-4\\-(3x^3&-8x^2&-5x&+6)\\ \hline\end{array} }

x

3

−(3x

3

+3x

2

−8x

2

+5x

−5x

−4

+6)