Respuesta :

semsee45

Answer:

140 pennies

Step-by-step explanation:

Information:

  • 1 penny (cent) = $0.01
  • 1 nickel = $0.05

Define the variables:

  • Let x be the number of pennies.
  • Let y be the number of nickels.

If the piggy bank contains 350 pennies and nickels:

[tex]\implies x+y=350[/tex]

If the piggy bank contains pennies and nickels worth $11.90:

[tex]\implies 0.01x+0.05y=11.90[/tex]

Rearrange the first equation to make y the subject:

[tex]\implies y=350-x[/tex]

Substitute the expression for y into the second equation and solve for x:

[tex]\implies 0.01x+0.05(350-x)=11.90[/tex]

[tex]\implies 0.01x+17.5-0.05x=11.90[/tex]

[tex]\implies -0.04x=-5.6[/tex]

[tex]\implies x=140[/tex]

Therefore, there are 140 pennies in the piggy bank.

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