Yes. in math you will get to a point where you will have to use ratios to do rates they kind of the same thing.
Answer:
x=1, y=-6. (1, -6).
Step-by-step explanation:
y=-6x
-2x-7y=40
------------------
-2x-7(-6x)=40
-2x+42x=40
40x=40
x=40/40
x=1
y=-6(1)=-6
Answer:
اhello : tan θ = - 12/5
Step-by-step explanation:
tan θ = sin θ / cos θ .... (*)
(cosθ)² + (sinθ)² = 1 ... (**)
theta is in quadrant 2 : cosθ ≤ 0
Substitute sinθ = 12/13 into (**) and solve for cosθ :
(cosθ)² + (12/13)² = 1
(cosθ)² = 1 - 144/169
(cosθ)² = 25/169
cosθ = - 5 /13 because cosθ ≤ 0
by (*) : tan θ = (12/13)/ (-5/13) = (12/13) ×(-13/5)
tan θ = - 12/5
Answer:
78 ml of 7% vinegar and 312 ml of 12% vinegar.
Step-by-step explanation:
Let x represent ml of 7% vinegar brand and y represent ml of 12% vinegar brand.
We have been given that chef wants to make 390 milliliters of the dressing. We can represent this information in an equation as:


We are also told that 1st brand 7% vinegar, so amount of vinegar in x ml would be
.
The second brand contains 12 vinegar, so amount of vinegar in y ml would be
.
We are also told that the chef wants to make 390 milliliters of a dressing that is 11% vinegar. We can represent this information in an equation as:

Upon substituting equation (1) in equation (2), we will get:







Therefore, the chef should use 78 ml of the brand that contains 7% vinegar.
Upon substituting
in equation (1), we will get:


Therefore, the chef should use 312 ml of the brand that contains 12% vinegar.