Answer:

1. Total MONEY = ₹20000

To milkman = 1/20 × 20000 = ₹1000

To food = 1/6 × 20000 = ₹3333.33

To Education = 1/10 × 20000 = ₹2000

Total expenditure = 1000+3333.33+2000 = ₹6333.33

Money left = 20000-6333.33 = ₹13666.67

2. 14.52×2.3 -11.25×(5.25-4.91)

= 33.396 - 11.25×0.34

= 33.396-3.825

= 29.571

3. 36-[18-{14-(15-4÷2×2)}]

= 36-[18-{14-(15-2×2)}]

= 36-[18-{14-(15-4)}]

= 36-[18-{14-11}]

= 36-[18-3]

= 36-15

= 21

4. p-1/p = 4....................(1)

Squaring both sides we get,

p^2 + 1/p^2 - 2.p.1/p = 16

=> p^2 + 1/p^2 = 18

Again CUBING (1) we get

p^3-3.p^2.1/p+3.p.1/p^2-1/p^3 = 64

=> p^3-3p+3/p-1/p^3 = 64

=> p^3-1/p^3-3(p-1/p) = 64

=> p^3-1/p^3-3.4 = 64

=> p^3-1/p^3 = 76

5. (6x^3y-12x^4y+15x^3y^2-3x^2y^2)÷ 3x^2y

= 6x^3y/3x^2y -12x^4y/3x^2y +15x^3y^2/3x^2y -3x^2y^2/3x^2y

= 2x-4x^2+5xy-y

6. x^(2m+3n).x^(3m-6n).x^(3n-5m)

= x^(2m+3n+3m-6n+3n-5m)

= x^0

= 1

7. (2a+3b)^2+(2a-3b)^2

= (2a+3b+2a-3b)^2 - 2.(2a+3b).(2a-3b)

[a2+b2 = (a+b)2-2ab]

= 4a^2-2.{(2a)^2-(3b)^2} [(a+b)(a-b)=a2-b2]

= 4a^2-8a^2+18b^2

= 18b^2-4a^2

I hope these help. Please MARK as brainliest.