x square -12x-45 factorisation
Answers
Answered by
14
Answer :
15, -3
Solution :
x² - 12x - 45
Splitting middle term
x² + 3x - 15x - 45 = 0
x(x + 3) - 15(x + 3) = 0
(x - 15)(x + 3) = 0
x = 15, x = -3
Answered by
0
Step-by-step explanation:
Look at the colour coding to see what each part of the trinomial tells us.
x
2
−
12
x
−
45
Find the factors of
45
which
subtract
to give
12
.
The signs will be
different
, there must be more
negatives.
The factors of 45 which we need are 15 and 3.
15
×
3
=
45
and
15
−
3
=
12
(
x
−
15
)
(
x
+
3
)
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