John purchased 8 tickets to a talent show and spent $25. he bought a combination of child tickets for $3 each and adult tickets for $4 each. how many child tickets did john purchase

Adult tickets (A): $4

Child tickets (C): $3

Total Cost:      4A + 3A = 25 → 1( 4A + 3A = 25)  → 4A + 3A = 25                

Total Tickets:    A +  C  = 8   →  -4(A + C = 8)       → -4A - 4C = -32

                                                                                          -C  = -8

                                                                                            C = 8

8 child tickets

pakistan's principal natural resources are arable land and water. about 25% of pakistan's agriculture accounts for about 21% [1] of gdp and employs about 43% of the labour force. in pakistan, the most agricultural province is punjab where wheat and cotton are the most grown.

(b) 240

step-by-step explanation:

first, we use the pythagorean formula using the given side lengths to find x. then we use x to find the side lengths. then we add the side lengths to find the perimeter.

pythagorean theorem formula:

a^2 + b^2 = c^2

(x - 20)^2 + (x - 40)^2 = x^2

x^2 - 40x + 400 + x^2 - 80x + 1600 = x^2

x^2 -120x + 2000 = 0

(x - 100)(x - 20) = 0

x - 100 = 0 or x - 20 = 0

x = 100 or x = 20

we see that the solution x = 20 must be discarded because it will give a negative side length and a side length of 0. the only valid solution is x = 100.

perimeter = sum of the lengths of the sides

perimeter = x + x - 20 + x - 40

perimeter = 3x - 60

replace x with 100.

perimeter = 3(100) - 60

perimeter = 300 - 60

perimeter = 240