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If g(x) is a liner function such that g(-1)=2 and g(3)=-4. Find the equation for g(x)

User Vampiire
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2 Answers

14 votes
14 votes

Answer:

Explanation:

1) This is a linear function so you have to use this ax + b = 0 formula.

ax represents the linear and b is the constant here.

2) Let's use our formula in this question.

g(x) = ax + b

3) Question says that you must write it -1 in the g(x) function to get 2. Then we write -1 instead of x.

g(-1) = a . -1 + b this should be equal to 2 >> 2 = a. -1 + b

4) The question gives us another equality: g(3) = -4. We are going to use the ax + b = 0 formula again.

g(3) = a . 3 + b this should be equal to -4 >> -4 = a . 3 + b

5) In the end we have 2 equalities.

a) 2 = -a + b

b) -4 = 3a + b

6) Let's multiply an equation with - .

a) -2 = a - b

b) -4 = 3a + b

7) If we add these two equation we can find a.

-6 = 4a

-3/2 = a

8) If we put -3/2 instead of a we can find b.

a) 2 = - . -3/2 + b >> 2 = 3/2 + b >> 2 - 3/2 = b >> b = 1/2

9) Now we find that a = -3/2 , b = 1/2. Let's write it in our formula.

g(x) = ax + b

g(x) = -3/2 . x + 1/2

g(x) = -3x/2 + 1/2 is our euqation for g(x).

User Leonardo Rick
by
3.4k points
14 votes
14 votes

Answer:

g(x)= −3/2x+1/2

User Jazi
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2.9k points