Astore sells jars of peanut butter that cost p dollars and jars of jelly that cost j dollars. winston purchased 3 jars of peanut butter and 2 jars of jelly for $11.50. peter purchased 2 jars of peanut butter and 4 jars of jelly for $13.00. how much does 1 jar of peanut butter cost? a. $2.00 b. $2.50 c. $3.00 d. $3.50

The cost of 1 jar of peanut butter is $2.50 ⇒ answer B

Step-by-step explanation:

* Lets change the story problem to equations to solve it

- The cost of a jar of peanut butter is p dollars

- The cost of a jar of jelly is j dollars

- Winston purchased 3 jars of peanut butter and 2 jars of jelly for $11.50

- Peter purchased 2 jars of peanut butter and 4 jars of jelly for $13.00

* Lets write the equations

∵ The cost of a jar of peanut butter is p dollars and the cost of a jar

   of jelly is j dollars

∵ Winston purchased 3 jars of peanut butter and 2 jars of jelly for $11.50

∴ 3p + 2j = 11.50 ⇒ (1)

∵ Peter purchased 2 jars of peanut butter and 4 jars of jelly for $13.00

∴ 2p + 4j = 13.00 ⇒ (2)

- Lets solve this system of equation by using elimination method

- Multiply equation (1) by -2

∴ -6p - 4j = - 23 ⇒ (3)

- Add equations (2) and (3)

∴ -4p = -10 ⇒ divide both sides by -4

∴ p = 2.5

∵ p is the cost of 1 jar of peanut butter

* The cost of 1 jar of peanut butter is $2.50

problem:

f(x) = - 2/3x + 5; f(5/2)

substitute 5/2 in for x:

f(5/2) = -2/3(5/2) + 5

simplify the right side:

f(5/2) = -5/3 + 5

f(5/2) = 10/3

f(5/2) = 10/3

i hope this !

just do 5.2 + 2 ( 7.2) and 1/3 x 3 (.9) and youv'e got your equation. 0.9( 9/10) + 7.2 ^2 = 16.4 hope i could !

step-by-step explanation: