SOLUTION: Anna scored 646 points making 355 shots, including 3-point field goals, 2-point field goals, and 1-point free throws. She made 27 more 2-point field goals than 3-point field goals.

Algebra ->  Matrices-and-determiminant -> SOLUTION: Anna scored 646 points making 355 shots, including 3-point field goals, 2-point field goals, and 1-point free throws. She made 27 more 2-point field goals than 3-point field goals.      Log On


   



Question 1012706: Anna scored 646 points making 355 shots, including 3-point field goals, 2-point field goals, and 1-point free throws. She made 27 more 2-point field goals than 3-point field goals. Write a system of three equations that represents the number of goals Anna made
Find the number of each type of goal she made for
3-point goals
2-point goals
1-point free throws

Found 2 solutions by Boreal, josmiceli:
Answer by Boreal(15235) About Me  (Show Source):
You can put this solution on YOUR website!
x=FT
y=2point
z=3 point
x+y+z=355
y-27=z
x+2y+3z=646
=========
x+y+y-27=355;;;x+2y+3(y-27)=646;;;x+2y+3y-81=646
x+2y-27=355
x+2y=382
x+5y=727
-3y=-345
y=115
x+575=727
x=152
z=88
(152,115,88)=355 shots
152+230+264=646 points

Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
Let +a+ =number of 1-point shots
Let +b+ =number of 2-point shots
Let +c+ =number of 3-point shots
---------------------------------
(1) +a+%2B+b+%2B+c+=+355+
(2) +1%2Aa+%2B+2%2Ab+%2B+3%2Ac+=+646+
(3) +b+=+c+%2B+27+
-----------------------
This is 3 equations and 3 unknowns,
so it is solvable
-------------------
Substitute (3) into (2)
(2) +1%2Aa+%2B+2%2A%28+c+%2B+27+%29+%2B+3%2Ac+=+646+
(2) +a+%2B+2c+%2B+54+%2B+3c+=+646+
(2) +a+%2B+5c+=+592+
---------------------
Substitute (3) into (1)
(1) +a+%2Bc+%2B+27+%2B+c+=+355+
(1) +a+%2B+2c+=+328+
----------------------
Subtract (1) from (2)
(2) +a+%2B+5c+=+592+
(1) +-a+-+2c+=+-328+
--------------------
+3c+=+264+
+c+=+88+
and
(3) +b+=+c+%2B+27+
(3) +b+=+88+%2B+27+
(3) +b+=+115+
and
(1) +a+%2B+b+%2B+c+=+355+
(1) +a+%2B+115+%2B+88+=+355+
(1) +a+=+355+-+203+
(1) +a+=+152+
-----------------
88 3-point goals
115 2-point goals
152 1-point free throws
-----------------------
check:
(2) +1%2Aa+%2B+2%2Ab+%2B+3%2Ac+=+646+
(2) +1%2A152+%2B+2%2A115+%2B+3%2A88+=+646+
(2) +152+%2B+230+%2B+264+=+646+
(2) +646+=+646+
You can check other 2 equations