Answer:
Number pencils Ava bought = 2
Explanation:
Price of pen = 2 $
Price of pencil = 1 $
Total money spent = 12 $
Let the number of pen be a and number of pencil be b.
2 a + b = 12 -----------------------------------Equation 1
We have, she bought 3 more pens than pencils
a - b = 3 -------------------------------------- Equation 2
Equation 1 +Equation 2,
2 a + b + a - b = 12 + 3
3a = 15
a = 5
Substituting in equation 2
5 - b = 3
b = 2
Number pencils Ava bought = 2
60 pens/ A dozen pens= 5 packs of a dozen pens
$44*5= $220 total spent
$20*60=$1200 total money a trader gets
$1200-$220=$980 in profits.
Hope I didn't mess up for your sake.
For rigt triangle with legs legnth a and b and hypotnuse legnth c
a^2+b^2=c^2
we are given
larger leg is 3 longer than smaller leg
hypotnuse is 6 longer than smaller
find smaller
ok so
first pick a smaller leg
lets say b is smaller
longer leg is 3 more than shorter leg
a is 3 more than b
a=3+b
and
hypontuse is 6 more than shorter
c=6+b
sub 3+b for a and 6+b for c in oroiginal equation'
a^2+b^2=c^2
(3+b)^2+b^2=(6+b)^2
9+6b+b^2+b^2=36+12b+b^2
2b^2+6b^2+9=b^2+12b+36
minus (b^2+12b+36) from both sides
b^2-6b-27=0
factor
(b-9)(b+3)=0
set equal to zero
b-9=0
b=9
b+3=0
b=-3
fasle, legnths cannot be negative
answer is shorter side=9 cm
subtract 6.4 from 25 = 1.3c + 18.6
