Step-by-step explanation:Let number of 49 cents =A
Let number of 33 cents=B
<u>A+B=45 equation 1</u>
1 $=100 cents
49 cents =.49 dollar
33 cents=.33 dollar
so .<u>49A+.33B=17.89 equation 2</u>
Add equation 1 and equation 2
since these are simultaneous equations
.49A+.33B=17.89
A+ B=45
so divide equation 2 by 100 we get
49A+33B=1789
A+B =45 multiply equation 1 by 33 on both the sides we get
<u>33A+33B=1485 equation 3</u>
so subtract equation 3 from equation 2 we get
49A+33B=1789 equation 2
<u>33A+33B=1485 equation 3</u>
<u>16A+0 =304</u>
16A=304
A=304/16
A=19
putting nalue of A in equation 1 we get
A+B=45
19+B=45
B=45-19
B=26
so number of 49 cent stamps are 19
and number of 33 cent stamps are 26
2(n - 1) + 4n = 2(3n - 1)
2n - 2 + 4n = 6n -2
6n - 2 = 6n - 2 (equal)
6n - 6n = 2 - 2
0 = 0
whatever value you put into the place of n, you'll get 0 = 0
The answer is (9,21) because is you plug in 9 for x, and add 12, you get 21.
