Answer:

Step-by-step explanation:
<h2>Equation of line in slope y-intercept form:</h2>

![\sf y - [-3] = \dfrac{1}{2}(x - 2)\\\\y + 3 = \dfrac{1}{2}x - 2*\dfrac{1}{2}\\\\y + 3 = \dfrac{1}{2}x-1\\\\](https://tex.z-dn.net/?f=%5Csf%20y%20-%20%5B-3%5D%20%3D%20%5Cdfrac%7B1%7D%7B2%7D%28x%20-%202%29%5C%5C%5C%5Cy%20%2B%203%20%3D%20%20%5Cdfrac%7B1%7D%7B2%7Dx%20-%202%2A%5Cdfrac%7B1%7D%7B2%7D%5C%5C%5C%5Cy%20%2B%203%20%3D%20%5Cdfrac%7B1%7D%7B2%7Dx-1%5C%5C%5C%5C)

Answer:
4 hours
Step-by-step explanation:
The general formula for distance, rate and time is:
d = rt, where distance is the product of rate multiplied by time
Given that one train is moving at a rate of 70 mph and one is moving at a rate of 62 mph in the opposite direction, the combined distance over time is equal to 528 miles. Using the variable 't' for time:
70t + 62t = 528
Combine like terms: 132t = 528
Divide both sides by 132: 132t/132 = 528/132 or t = 4 hours
4 sin^2 θ + 13cos^2 θ = 7
sin^2 θ = 1 - cos^ θ
4 - 4cos^2 θ + 13cos^2 θ = 7
9cos^2 θ = 3
cos^2 θ = 1/3
cos θ = # (1/3) # - square root
Square root of (1/3) has +1/3 and -1/3 as values of cos
Find the key angle by doing the cos inverse of #1/3
K.A = cos^-1 #(1/3) = 0.955
θ lies in all 4 quadrants
The values of θ are:
θ = 0.955, 2.186, 4.096, 7.23
Ignore 0.955, 2.186, 4.096, 7.23 as they are out of range pi/2 = 1.571
The the value of θ = 0.955 = 0.96 (to 2 d.p) radian
Hope it helped!
Answer:
92.
Step-by-step explanation:
By proportion the mass of zinc = (345/ 15) * 4
= 92.