When you evaluate the function f (x) = 4 • 7 ^ x for x = -1 you get:
f (-1) = 4 * 7 ^ -1
f(-1) = 4* 1/7
f (-1) = 0.5714
The next part of the question is not clear. If it refers to the function at x = 2 then:
f (2) = 4 * 7 ^ (2)
f(2) =4*49
f (2) = 196
If it refers to it in x ^ 2
f (x ^ 2) = 4 * 7 ^ (x ^ 2)
Five hundred ninety two thousand six hundred eighty two
All you have to do is substitute the y value from the 1st equation into the second equation and solve...
a) y= 2-x
5x + 4y = 5
Substitute (2-x) into the second equation anywhere there is a y...
5x + 4y = 5
5x + 4(2-x) = 5
Now solve
5x + 8 - 4x = 5
5x - 4x + 8 = 5
x + 8 = 5
x = -3
Now that you have a solution for x, substitute -3 into either of the original equations anywhere there is an x then solve for y...
y = 2 - x
y = 2 - (-3)
y = 2+3 = 5
You solved for x and got -3 and solved for y and got 5, so your solution set is
(-3, 5).
Now check it by substituting both numbers into one of the original equations and you should have a true statement if it is correct...
y = 2 - x
5 = 2 - (-3)
5 = 2+3
5 = 5
True statement... it checks!
note* during the check, if the equation would have worked out to something like 2 = 5, then that is a false statement therefore the solution set would be wrong and you'd have to go back and find the mistake.
Answer:
-3
Step-by-step explanation:
The product (the result of a multiplication) of 4 and a number. Let x be the unknown number:
4 · x = 4x
Plus 17:
4x + 17
Is 5:
4x + 17 = 5
Solve:
4x = 5 - 17
4x = -12
x = -12 ÷ 4
x = -3
