S=number of 6 cent stamps
t=number of ten cen stamps
e=number of 8 cent stamps
w=number of 20 cents stamps=2
cost=500 cents
6s+10t+8e+20w=500
w=2 since two 20 cent stamps wer bought
6s+10t+8e+40=500
minsu 40 both sides
6s+10t+8e=460
divide both sides by 2 to simplify
3s+5t+4e+230
also
10 more 6 cent than 10 cent
s=10+t
8 cent stamps is 3 times 10 cent stamps
e=3t
sub
s=10+t
e=3t
3(10+t)+5t+4(3t)+230
30+3t+5t+12t=230
30+20t=230
minus 30
20t=200
divid 20
t=10
sub back
s=10+t
s=10+10
s=20
e=3t
e=3(10)
e=30
20 six cent
30 eight stamp
10 ten cent
2 twenty cent
Answer:
the answer is option D
Step-by-step explanation:
if you add the no of students in favour of the survey
32+42+58+64=192
which makes the first option incorrect.
The opinion of tenth and eleventh graders are not identical.
11th and 12th graders gave a favourable response
so options A,B and C are incorrect
(4.3×10²) × (4.0×10⁻³) in scientific notation?
(4.3 x 4.0) x (10² x 10⁻³) = 17.2 x (10² x 10⁻³) =
= 17.2 x 10²⁻³ = 17.2 x 10⁻¹ = 1.72 x 10¹ x 10⁻¹ = 1.72 x 10¹⁻¹ = 1.72 x 10⁰ = 1.72 x 1
Answer : 1.72 x 10⁰ = 1.72
Hope this helps!
