Answer:
740
Step-by-step explanation:
The n th term of an arithmetic series is
= a₁ + (n - 1)d
where a₁ is the first term and d the common difference
Given a₃ = 7 and a₇ = (3 × 7) + 2 = 21 + 2 = 23 , then
a₁ + 2d = 7 → (1)
a₁ + 6d = 23 → (2)
Subtract (1) from (2) term by term
4d = 16 ( divide both sides by 4 )
d = 4
Substitute d = 4 into (1)
a₁ + 2(4) = 7
a₁ + 8 = 7 ( subtract 8 from both sides )
a₁ = - 1
The sum to n terms of an arithmetic series is
=
[ 2a₁ + (n - 1)d ] , thus
=
[ (2 × - 1) + (19 × 4) ]
= 10(- 2 + 76) = 10 × 74 = 740
The length of the hypothenuse or the value of x is equal to 19.53
Data;
- hypothenuse = x
- adjacent = 11.2
- opposite = 16
<h3>Pythagoras's Theorem</h3>
To solve this problem, we have to use Pythagoras's theorem which is used to find the missing side in a right angle triangle if we have at least two sides.
The formula for this is

Let's substitute the values and solve for the missing side

The length of the hypothenuse or the value of x is equal to 19.53
Learn more Pythagoras theorem here;
brainly.com/question/3317136
If a< c< b then a<c and c<b
Separate the equation into 2 separate ones and solve them:
X-9 < 4x +3
Subtract 3 from both sides:
X-12 < 4x
Subtract x from both sides:
-12< 3x
Divide both sides by 3:
X > -4
4x+3 < 27
Subtract 3 from both sides
4x < 24
Divide both sides by 4
X <6
Combine to get one inequality:
-4<x<6