Given/equations formed from text:
I: l=w+3
II: A=l*w
III: new area B=(l-2)*w
IV: B=A-30
substitute l in II with I to remove l:
II': A=l*w=
(w+3)*w=
w^2+3w
substitute l in III with I to remove l:
III': B=(l-2)*w=
(w+3-2)*w=
(w+1)*w=
w^2+w
substitute A and B from II' and III' into IV:
B=A-30
w^2+w=w^2+3w-30
30=2w
w=15
insert w=15 into I:
l=15+3=18
->
A) dimensions of full size rectangle are width 15 and length 18
dimensions of reduced size rectangle are width 15 and length 16
B) full size: 15*18=10*18+5*18=180+90=270cm^2
reduced size: 15*16=10*16+5*16=160+80=240cm^2
Answer:
Option A.Exponential decay, 55% decrease
we have
This is a exponential function of the form
where a is the initial value
b is the base
b=(1+r)
r is the rate of change
In this problem
a=54
b=0.45
so
0.45=1+r
r=0.45-1
r=-0.55
Convert to percentage
r=-55% ------> is negative because is a exponential decay
Answer:
(3, 3 )
Step-by-step explanation:
Given the 2 equations
3x - y = 6 → (1)
6x + y = 21 → (2)
Adding the 2 equations term by term will eliminate y, that is
(6x + 3x) + (y - y) = (21 + 6), that is
9x = 27 (divide both sides by 9 )
x = 3
Substitute x = 3 into either (1) or (2) and solve for y
Using (2), then
(6 × 3) + y = 21
18 + y = 21 ( subtract 18 from both sides )
y = 3
Solution is (3, 3 )
Answer:
6
Step-by-step explanation:
your answer is 6 because she did 12 in 1hr and the other 12 in 3hr so you take 3=1+4 and divide 24 by 4 which is 6
