Answer:
Step-by-step explanation:
Let y represent students in the class
55% of y = 78
0.55y= 78
y = 142
3x+3=3y ⇒ 3y-3x=3 ⇒3(y-x)=3 ⇒ y-x=1
2x-6y=2 ⇒ 2(x-3y)=2 ⇒ x-3y=1
We must to collect two equations.
x's is lost;
y-3y=2
-2y=2
y=-1 ; x-3.(-1)=1 ⇒ x=-2
Answer is (-2,-1)
Answer:
= 21x - 1
Step-by-step explanation:
= (4x + 12x) + (5x - 1)
= 4x + 12x + 5x - 1
= 16x + 5x - 1
= 21x - 1
Answer:
9/4:3/8=9/4×8/3=72/12=24/4=6/1=6
Answer:
S.I= 640
Step-by-step explanation:
I=prt
where p= $8,000
and r= 4%
and t= 2 years
$8,000×4%×2
8,000×4/100×2
80×4×2
=640
Therefore The S.I = 640.
