**NCERT SOLUTIONS CLASS 9 MATHEMATICS**

**Exercise 4.2**

**Q.1.** Which one of the following options is true, and why? y = 3x + 5 has

(i) a unique solution, (ii) only two solutions, (iii) infinitely many solutions

**Q.2.** Write four solutions for each of the following equations:

(i) 2x + y = 7 (ii) πx + y = 9 (iii) x = 4y

**Q.3.** Check which of the following are solutions of the equation x - 2y = 4 and which are not:

(i) (0, 2) (ii) (2, 0) (iii) (4, 0) (iv) ($\sqrt{2}$, 4$\sqrt{2}$) (v) (1, 1)

**Q.4.** Find the value of k, if x = 2, y = 1 is a solution of the equation 2x + 3y = k.