I have a couple of problems that i am stuck on. They are word problem.

1 Soybean meal is 12% protien; cornmeal is 6% protien. How many pounds of each should be mixed together on order tyo get 280 pounds of mixture that is 11% protien?
How many pounds of the cornmeal should be in the mixture?
How many pounds of soybean meal should be in the mixture?

also this problem
In 1993, the life expectancy of males in a certian country was 65.9 years. In 1995, it was 69.4 years. Letting E represent the life expectancy in year t and let t represent the number of years since 1990.
The linear function E(t) that fits the data is
E(t)=___t + ___
Use the function to perdict the life expectancy of males in 2003.
E(13)=____
Making sure to round to the nearest tenth.

To solve the first problem, we can use a system of equations. Let's start by assigning variables to the unknown quantities.

Let x represent the pounds of soybean meal and y represent the pounds of cornmeal.

According to the problem, we have the following information:

1. The total weight of the mixture is 280 pounds: x + y = 280

2. The mixture should contain 11% protein. This means that the sum of the protein in the soybean meal and the protein in the cornmeal should equal 11% of the total weight of the mixture.

The protein in the soybean meal is 12% of x, and the protein in the cornmeal is 6% of y. So, we can write another equation:

0.12x + 0.06y = 0.11 * 280

Simplifying the equation, we have:

0.12x + 0.06y = 30.8

Now we have a system of equations:

1. x + y = 280
2. 0.12x + 0.06y = 30.8

To solve this system, we can use the method of substitution or elimination. Let's use the method of substitution.

1. Solve equation 1 for x:
x = 280 - y

2. Substitute x in equation 2:
0.12(280 - y) + 0.06y = 30.8

Expanding and simplifying the equation, we get:

33.6 - 0.12y + 0.06y = 30.8

Combining like terms, we have:

-0.06y = -2.8

Dividing both sides of the equation by -0.06, we get:

y = 46.67

So, approximately 46.67 pounds of cornmeal should be in the mixture.

To find the pounds of soybean meal, substitute the value of y into equation 1:

x + 46.67 = 280

Solving for x, we get:

x = 233.33

So, approximately 233.33 pounds of soybean meal should be in the mixture.

Therefore, the mixture should contain approximately 46.67 pounds of cornmeal and 233.33 pounds of soybean meal.

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To solve the second problem, we need to find the linear function that fits the given data.

According to the problem, we have two data points:

In 1993 (t = 3 since 1990): E(3) = 65.9
In 1995 (t = 5 since 1990): E(5) = 69.4

We can find the slope of the linear function using the slope formula:

m = (E(5) - E(3)) / (5 - 3)

Substituting the values, we have:

m = (69.4 - 65.9) / (5 - 3)
m = 3.5 / 2
m = 1.75

Now we can substitute the slope and one of the data points into the equation:

E(t) = mt + b

Using E(3) = 65.9 and m = 1.75, we can solve for b:

65.9 = 1.75(3) + b
65.9 = 5.25 + b
b = 65.9 - 5.25
b = 60.65

So, the equation for the linear function is:

E(t) = 1.75t + 60.65

To predict the life expectancy in 2003, we substitute t = 13 into the equation:

E(13) = 1.75(13) + 60.65

Calculating the value, we get:

E(13) = 22.75 + 60.65
E(13) = 83.4

Therefore, the predicted life expectancy for males in 2003 is approximately 83.4 years (rounded to the nearest tenth).