Answer:
a=20 m²
b=21 cm²
c=36 dm²
Step-by-step explanation:
A) 12²+16²=a²
144+256=a²
400=a²
√400=a
a=20
B) 28²+b²=35²
784+b²=1225
b²=1225-784
b²=441
b=√441
b=21
C) c²+15²=39²
c²+225=1521
c²=1296
c=√1296
c=36
Answer:
x= -8 , y = 5
x= 25/4 , y = 1/4
Step-by-step explanation:
substitute first eqn into the second eqn:
(7 - 3y)^2 -y^2 = 39
49 - 42y + 9y^2 - y^2 = 39
8y^2 - 42y +10 =0
4y^2 - 21y + 5 = 0
(4y-1) (y-5) = 0
y= 1/4 , 5
when y=1/4
x = 7- 3/4
=25/4
when y= 5
x = 7- 15
= -8
<em>x = - 2</em>
<em>y = 5</em>
- <em>Step-by-step explanation:</em>
<em>Hi there ! </em>
<em>2x + 9 = y</em>
<em>y = - 4x - 3</em>
<em>
</em>
<em>equality</em>
<em>2x + 9 = - 4x - 3</em>
<em>2x + 4x = - 9 - 3</em>
<em>6x = - 12</em>
<em>x = - 12 : 6</em>
<em>x = - 2</em>
<em>replace x = - 2</em>
<em>2(-2) + 9 = y</em>
<em>- 4 + 9 = y</em>
<em>y = 5</em>
<em>Good luck !</em>
<em />
<em />
Answer:
-4 <n <= 5
Step-by-step explanation:
Open at -4 and closed at 5 on number line so the inequality should be
-4 <n <= 5
