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Identities — MATHS STD 8 — Question

ICSE BoardEnglish MediumSTD 8MATHSIdentities4 Marks
Question
Use the direct method to evaluate the following products : $(5a + 16) (3a – 7)$
✓

Answer

$(5a + 16) (3a – 7) $
$= (5a \times 3a) + (5a \times −7) + (16 \times 3a) + 16 −7= 15a^2 + (−35a) + 48a + (−112)$
$= 15a^2− 35a + 48a − 112$
$= 15a^2 + 13a − 112$

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