Choice B is the correct answer. We can use elimination by multiplying the second equation by 3.
Step 1: Multiply the second equation by 3:
3(2x−y)=3(5)6x−3y=15
Step 2: Add to the first equation:
(4x+3y)+(6x−3y)=21+1510x=36x=3.6
That gives non-integer. - First: 4(3)+3(3)=12+9=21 ✓
- Second: 2(3)−3=6−3=3 eq5
Step 1: Multiply the second equation by 3:
6x−3y=9
Step 2: Add to the first equation:
10x=30x=3
Step 3: Substitute into second equation:
2(3)−y=36−y=3y=3
Solution: (3,3)
Verification: 4(3)+3(3)=21 ✓ and 2(3)−3=3 ✓
💡 Strategic Tip: Choose the method that minimizes fractional arithmetic.
Choice A is incorrect because2(2)−4.33=−0.33 eq3.
Choice C is incorrect because4(4)+3(35)=16+5=21 ✓, but 2(4)−35=319 eq3.
Choice D is incorrect because4(1)+3(317)=4+17=21 ✓, but 2(1)−317=−311 eq3.