So for this you are going to be using a system of equations. The first equation is gonna equal the # of wheels and the second equation is gonna equal the # of pedals.
Let x equal # of tricycles and y equal # of unicycles.
The first equation is gonna be [tex]3x+y=337[/tex]
The second equation is gonna be [tex]2x+2y=330[/tex]
For this, I'll be using the substitution method. And to be able to do that, you'll be subtracting 3x on each side of the first equation to get [tex]y=-3x+337[/tex] .
And with this, you are going to substitute y in the second equation for (-3x+337) since that is the equivalent to y according to the first equation; and your second equation should look like this: [tex]2x+2(-3x+337)=330[/tex] . From here we can solve for x.
First multiply 2 with (-3x+337), and your equation should look like [tex]2x-6x+674=330[/tex]
Combine like terms to get [tex]-4x+674=330[/tex]
Subtract 674 on each side to get [tex]-4x=-344[/tex]
And then divide -4 on each side, and your answer should be [tex]x=86[/tex]
Now that we know that x is 86, we can replace x for 86 in either equation to solve for y. For this, i'll be substituting in the first equation.
[tex]3(86)+y=337[/tex]
Multiply 86 with 3 to get [tex]258+y=337[/tex]
And then just subtract 258 on each side to get [tex]y=79[/tex]
So since we now know that there are 86 tricycles and 79 unicycles, we just need to subtract them to get the final answer.
[tex]86-79=7[/tex]
There are 7 more tricycles than unicycles.
