Question

questions :
17. Solve the following pair of linear equations
3x + 2y = 11
Sx-2y - 13
18. Find the sum of first 20 terms of AP. 3, 7, 11, 15 using the formula
19. Find the discriminant of the quadratic equation 2** ***4*0. hence
find the nature of its roots.
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20. Find the distance between the points A (8.3) and B12, 11) by
distance formula
21.
A box contains 28 bulbs of which 7 bulbs are defective, a bulb w drawn
randomly from the box. Find the probability of picking a non delect
bulb.​

Answer 1

Answer:

Step-by-step explanation:

3x + 2y =11 and 5x –2y = 13

By elimination method

3x + 2y =11 ... (i)

5x –2y = 13 ... (ii)

Multiplying equation (i) by (ii), we get

15x + 10y = 55 ... (iii)

15x –6y = 39 ... (ii)

Subtracting equation (ii) from equation (iii), we get

16y = 16

y = 16/16

y = 1

Putting the value in equation (i), we get

3x + 2 × 1 =11

3x + 2 =11

3x = 11 - 2

3x = 9

x = 9 /3

x = 3

Hence, x = 3 and y = 1