Answer:
use -9 to multiply the first equation
use -4 to multiply the second equation.
Step-by-step explanation:
5x-4y=28.....eqn (1)×-9
3x-9y=30....eqn(2)×-4
-45x+36y=-252
-(-12x+36y=-120)
therefore, -33x÷33 =-132÷-33
x=4.
substitute (x=4) in any of the equation. I'm just going to use eqn 1.
5x-4y=28
5(4)-4y=28
20-4y=28
-4y =28-20
-4y÷-4 = 8÷-4
y=-2
so, x=4, y=-2
Note: for proof of answers substitute the answers for x and y and see if you have the same result...e.g
5(4)-4(-2)=28.
Answer:
0.225 L of milk, would be
required if she uses 450 m L of water.
Step-by-step explanation:
Here, to make the shake, ingredients used by Dina are:
40 m L of chocolate syrup,
200 m L of milk, and 400 m L of water.
So, here Amount of water used = 2 x ( Amount of Milk used) ....... (1)
Now,again the amount of water used by Dona = 450 m L
Let us assume the milk used by her = k m L
⇒ 450 m L = 2 x ( k m L) ( from (1))
or, 450 = 2 k
⇒ k = 450/2 = 225
⇒ k = 225 m L
Also, 1 m L = 0.001 L
So, 225 m L = 225 x 0.001 = 0.225 L
⇒ k = 0.225 L
Hence, 0.225 L of milk, would be
required if she uses 450 m L of water.
