For this, you have to understand the ratios of a 30,60,90 triangle. The ratio(in order) is x, x(sqrt 3), 2x (following the 30,60,90 pattern y'know). Well, we know the length of the hypotenuse, 4.2, so let's use ratios to figure the other sides out. The ratio of AC is x and the ratio of AB is 2x, so 2x/2=x=2.1. One side down. BC has a ratio of x(sqrt 3). We already know x so we can substitute it in. We get 2.1(sqrt 3). To calculate the area, use the formula 1/2(bh). Inputting the values in, we get 1/2(2.1*(2.1(sqrt 3)). This can be calculated to around 3.82. To calculate the perimeter, take the sum of the sides. By adding the sides together, we get about 9.98. Hope you can now understand how to do these kinds of questions.
Note that if we add each side of the 2 equations, y will cancel out:
-12x-y+(17x+y)=6+4
5x=10
x=2
Substituting x=2 in either of the equations, we find the value of y.
Let's use the first equation:
-12x-y=6
-24-y=6
-y=24+6
-y=30, so y=-30.
Thus, the solution is (2, -30)
Answer: C
17.5x12=210
210 divided by 14=15
15x2.50=37.5
37.5
17.5 is feet so you need to divide by 12 for inches which gets 210 and you need each necklace to be 14 inches so you need to divide 210 by 14 which is 15 each necklace costs 2.50 so you multiply 2.50x15
You get 37.5
Remember x is x and f(x) is same thing as y.
f(5) = 4
It is same thing as saying, when x = 5, y aka f(x) should be 4. Aka the point (5,4)
Let’s look at D, if x =5 then f(x)=5? No, it should equal 4. So this is wrong. It is also not linear. So NOT D
Lets look at C, if x =5 then
1/5(5)+3 =
5/5 + 3 =
1+3 =
4
So, f(x) aka y = 4. Is this correct? Yes when x =5, y indeed should equal 4, but it is not linear. So NOT C
Lets look at B, if x=5 then,
2^5 -28 =
32 - 28 =
4
So, f(x) aka y = 4. Is this correct? Yes when x =5, y indeed should equal 4, AND it is linear SO THE ANSWER IS B
Check A too, it gets y=14 so thats wrong as it is not 4.
