Share

# Solve X2 + 7x = 7 and Give Your Answer Correct to Two Decimal Places - ICSE Class 10 - Mathematics

#### Question

Solve x2 + 7x = 7 and give your answer correct to two decimal places

#### Solution

Given quadratic equation is x2 + 7x = 7

=> x^2 + 7x - 7 = 0

Comparing with ax^2 + bx +c =0 we have a = 1, b = 7 and c = -7

x = (-b+-sqrt(b^2 -4ac))/(2a)

=> x = (-7 +- sqrt(7^2 - 4 xx 1 xx (-7)))/(2 xx1)

=> x = (-7+- sqrt77)/2

=> x  = (-7+- 8.77)/2

=> x = (-7+8.77)/2 and x = (-7-8.77)/2

=> x = 1.77/2 and x = (-15.77)/2

=> x = 0.885 and x = -7.885

=> x = 0.89 and x = -7.89 (correct to two decimal places)

Is there an error in this question or solution?

#### Video TutorialsVIEW ALL [5]

Solution Solve X2 + 7x = 7 and Give Your Answer Correct to Two Decimal Places Concept: Quadratic Equations.
S