Sagot :
Let the number of algebra problems be x
Let the number of geometry problems be y
Total problems = 27
Total time = 90 minutes
Time for one algebra problem = 2 minutes
Time for one geometry problem = 5 minutes
Hence,
x + y = 27
→ x = 27 – y
Û¦Û¦Û¦Û¦Û¦Û¦Û¦Û¦Û¦Û¦
[tex]2x + 5y = 90[/tex]
[tex]2(27 - y) + 5y = 90[/tex]
[tex]2(27) - 2y + 5y = 90[/tex]
[tex]3y = 90 - 54[/tex]
[tex]3y = 36[/tex]
[tex]y = \frac{36}{3} [/tex]
[tex]y = 12[/tex]
[tex]x = 27 - 12 = 15[/tex]
••••••••••
Answer:
→ He had 15 algebra problems for the homework