Answer:
20
Step-by-step explanation:
x-2y=6 and x+y=10
Multiply the second equation by 2
2x+2y = 20
Answer:
(2, -3)
Step-by-step explanation:
Apparently, the equations are supposed to be ...
The solution for x can be found by subtracting the second equation from the first:
(4x +y) -(3x +y) = (5) -(3)
x = 2 . . . . . . . matches the second answer choice
Y can be found from either equation:
y = 5 - 4x . . . . . subtract 4x from the first equation
y = 5 -4(2) = -3
The solution is (x, y) = (2, -3).
The flagstones are 0.8*0.5=0.4 square meters. 169/0.4=422.5 tiles. 422.5 tiles multiplied by 1.2 for waste is 507 tiles, the amount that Liam should buy.
1 mole of any substance is approximately 6.022*10^23 atoms (Avogadro's number)
So
(4.90*10^31 atoms) * (1 mole / 6.022*10^23 atoms) = 8.14*10^7 moles
