Substitute the values into y = ax + b. For 10 modules, 400 = 10a + b. For 14 modules, 500 = 14a + b. Subtracting the equations gives 4a = 100, which results in a = 25 and b = 150.
A learning platform charges a fixed monthly fee and an additional cost per digital learning module accessed. A student observes that when she accessed 10 modules, her bill was rupees 400. When she accessed 14 modules, her bill was rupees 500. If the monthly bill y depends on the number of modules accessed, x, according to the relation y = ax + b, find the values of a and b.
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To find the constants, form two linear equations using the given data points (10, 400) and (14, 500) according to the relation y = ax + b. This gives 400 = 10a + b and 500 = 14a + b. Subtracting the first equation from the second equation helps eliminate b, yielding 4a = 100, which means a = 25. Substituting a = 25 back into the first equation yields b = 150. Thus, a is 25 and b is 150
For more NCERT Solutions for Class 9 Maths Ganita Manjari Chapter 2 Introduction to Linear Polynomials (2026-27):
https://www.tiwariacademy.com/ncert-solutions/class-9/maths/ganita-manjari-chapter-2/