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Standard VIII

Mathematics

Algebraic Expressions

iii Find and ...

Question

Question 10(iii)
Find and correct the errors in the following mathematical statement. Substituting $x = - 3$ in
$x^{2} + 5 x g i v e s (- 3)^{2} + 5 (- 3) = - 9 - 15 = - 24$

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Solution

$F o r x = - 3 x^{2} + 5 x = (- 3)^{2} + 5 (- 3) = 9 - 15 = - 6$

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Similar questions

Find and correct the errors in the following mathematical statement, Substituting $x = - 3$ in
$x^{2} + 5 x + 4$ gives $(- 3)^{2} + 5 (- 3) + 4 = 9 + 2 + 4 = 15$

Find and correct the errors in the following mathematical statement. Substituting x = −3 in

(a) x² + 5x + 4 gives (−3)² + 5 (−3) + 4 = 9 + 2 + 4 = 15

(b) x² − 5x + 4 gives (−3)² − 5 (−3) + 4 = 9 − 15 + 4 = −2

Q. Find and correct error in the following mathematical statement.
Substituting

x = - 3

in:
(a)

x^{2} + 5 x + 4

gives

(- 3)^{2} + 5 (- 3) + 4 = 9 + 2 + 4 = 15

(b)

x^{2} - 5 x + 4

gives

(- 3)^{2} - 5 (- 3) + 4 = 9 - 15 + 4 = - 2

(c)

x^{2} + 5 x

gives

(- 3)^{2} + 5 (- 3) = - 9 - 15 = - 24

Substituting $x = - 3$ in $x^{2} + 5 x$ gives $3^{2} + 5 (- 3) = - 9 - 15 = - 24.$

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Algebraic Expressions

Standard VIII Mathematics

Question 10(iii) Find and correct the errors in the following mathematical statement. Substituting x=−3 in x2+5x gives (−3)2+5(−3)=−9−15=−24

For x=−3x2+5x=(−3)2+5(−3)=9−15=−6

Question 10(iii)
Find and correct the errors in the following mathematical statement. Substituting $x = - 3$ in
$x^{2} + 5 x g i v e s (- 3)^{2} + 5 (- 3) = - 9 - 15 = - 24$

$F o r x = - 3 x^{2} + 5 x = (- 3)^{2} + 5 (- 3) = 9 - 15 = - 6$