Answer:
The answer to your question is below
Step-by-step explanation:
Question 1
x = 5 Equation l
2x + y = 10 Equation ll
- Substitute Equation l in equation ll
2(5) + y = 10
y = 10 - 10
y = 0
- Solution (5, 0)
Question 2
x + 16y = 20 Equation l
x = 4y Equation ll
Substitute equation ll in equation l
4y + 16y = 20
20y = 20
y = 20/20
y = 1
-Find x
x = 4(1)
x = 4
-Solution
(4, 1)
Question 3
2x + 8y = 20 Equation l
x = 2 Equation ll
-Substitute equation ll in equation l
2(2) + 8y = 20
4 + 8y = 20
8y = 20 - 4
8y = 16
y = 16/8
y = 2
- Solution
(2, 2)
Area=1/2 times base times height
note:bh=base times height
a=1/2bh
b=width
h=-4+2w
h=2w-4
subsitute
a=1/2w(2w-4)
a=1/2(2s^2-4w)
a=w^2-2w
a=63
63=w^2-2w
subtract 63 from both sdies
0=w^2-2w-63
factor
find what 2 numbers multiply to get -63 and add to get -2
the numbers are -9 and 7
so
0=(w-9)(w+7)
if xy=0 then x and/or y=0
so
w-9=0
w+7=0
solve each
w-9=0
add 9 to both sdies
w=9
w+7=0
subtract 7 from both sides
w=-7
width cannot be negative so this can be discarded
width=9
subsitute
l=2w-4
l=2(9)-4
l=18-4
l=14
legnth=14 in
width/base=9 in
Answer:
D
Step-by-step explanation:
you have to multiply .79 to both a and 1.2. A is wrong because it's saying we need to multiply .79 to 1.2lb. which is the weight of oranges and the total cost of apples and oranges which is 6.27.