Answer:
30 ml of 45% salt solution and 20 ml of 30% salt solution.
Step-by-step explanation:
Let x be the amount of 45% salt solution and y be the amount of 30% salt solution
the two equation will be:
x+y=60 -- A
0.45x+0.3y=0.4(60) -- B
Solve by substitution
Rewrite Equation A
x+y=60
x=60-y --- C
Substitute C into B
0.45(60-y)+0.3y=24
27-0.45y+0.3y=24
-0.15y=-3
y=20
<u>Substitute</u> the y=20 into equation C
x=60-20
x=30
Therefore, there was 30 ml of 45% salt solution and 20 ml of 30% salt solution.
Answer:
m<Q = 93 degrees
m<R = 87 degrees
Step-by-step explanation:
Given the following angles;
m<Q = 9x-6
m<R = 8x-1
Looking at Devin's work, we will see that he the sum of both angles is 180 degrees
Hence m<Q + m<R = 180
9x - 6 + 8x - 1 = 180
9x+8x-6-1 = 180
17x - 7 = 180
17x = 180 + 7
17x = 187
x = 187/17
x = 11
Get m<Q
m<Q = 9x - 6
m<Q = 9(11) - 6
m<Q = 99 - 6
m<Q = 93 degrees
Get m<R
m<R = 180 - m<Q
m<R = 180 - 93
m<R = 87degrees
Answer:
the answer is the first one I think but I'm pretty sure
Answer:
bnb,j
Step-by-step explanation:
Answer:
S₁₆ = 328
Step-by-step explanation:
the nth term of an arithmetic sequence is
= a₁ + (n - 1)d
where a₁ is the first term and d the common difference
given a₄ = 7 and a₇ = 16 , then
a₁ + 3d = 7 → (1)
a₁ + 6d = 16 → (2)
subtract (1) from (2) term by term to eliminate a₁
0 + 3d = 9
3d = 9 ( divide both sides by 3 )
d = 3
substitute d = 3 into (1) and solve for a₁
a₁ + 3(3) = 7
a₁ + 9 = 7 ( subtract 9 from both sides )
a₁ = - 2
the sum to n terms of an arithmetic sequence is
= 
[ 2a₁ + (n - 1)d ]
with a₁ = - 2 and d = 3 , then
S₁₆ = 
[ (2 × - 2) + (15 × 3) ]
= 8(- 4 + 45)
= 8 × 41
= 328
