Find and correct the errors in the following mathematical statement. Substituting x = −3 in (a) x^2 + 5x + 4 gives (−3)^2 + 5 (−3) + 4 = 9 + 2 + 4 = 15 (b) x^2 − 5x + 4 gives (−3)^2 − 5 (−3) + 4 = 9 − 15 + 4 = −2 (c) x^2 + 5x gives (−3)^2 + 5 (−3) = −9 − 15 = −24
Answers
Answer:
Solution:
An equation is a mathematical statement with an 'equal to' symbol between two algebraic expressions that have equal values.
a) x2+ 5x + 4 gives (-3)2 + 5(-3) + 4 = 9 + 2 + 4 = 15
For x = -3
L.H .S = x2 + 5x + 4
= (-3)2 + 5(-3) + 4
= 9 -15 + 4
= 13 -15
= -2
But RHS is given as 15
Thus, L.H.S ≠ R.H.S
The correct statement is x2+ 5x + 4 gives (-3)2 + 5(-3) + 4 = 9 -15 + 4 = -2
(b) x2 - 5x + 4 gives (-3)2 - 5(-3) + 4 = 9 - 15 + 4 = -2
For x = -3
x2 - 5x + 4
= (-3)2 - 5(-3) + 4
= 9 +15 + 4
= 28
But, RHS is given as -2
Thus, L.H.S ≠ R.H.S
The correct statement is x2 - 5x + 4 gives (-3)2 - 5(-3) + 4 = 9 + 15 + 4 = 28
(c) x2 + 5x gives (-3)2 + 5(-3) = - 9 - 15 = -24
For x = - 3
x2 + 5x
= (-3)2 + 5(-3)
= 9 -15
= - 6
But, RHS is given as -24
Thus, L.H.S ≠ R.H.S
The correct statement is x2 + 5x gives (-3)2 + 5(-3) = 9 - 15 = - 6
Answer:
Solution
verified
Verified by Toppr
(a) x
2
+5x+4=(−3)
2
+5(−3)+4=9−15+4=−2
(b) x
2
−5x+4=(−3)
2
−5(−3)+4=9+15+4=28
(c) x
2
+5x=(−3)
2
+5(−3)=9−15=−6