Answer:
23
x^
4
y^
7
Step-by-step explanation:
400 reduced by 4 times my age is 116...
400 - 4x = 116
-4x = 116 - 400
-4x = - 284
x = -284/-4
x = 71 <===
Answer:
13 l of 15%, 13 l of 25%, 26 l of 70%
Step-by-step explanation:
solutions:
final solution:
This includes 0.45*52l= 23.4 l acid
Let's assume:
- amount of 15% solution= x
- amount of 25% solution= y
- amount of 70% solution= z
- and we have z=2y
so there are 2 equation:
or
- x+y+2y= 52 ⇒ x+3y= 52 ⇒ x= 52- 3y
- 0.15x+1.65y=23.4
- 0.15*(52-3y)+1.65y=23.4
- 7.8-0.45y+1.65y=23.4
- 1.2y=23.4-7.8
- 1.2y= 15.6
--------
- x= 52- 3*13= 13 l
- z= 2y= 2*13= 26 l
<span>2x+38=180 since all triangles add up to 180 and we have 38 as a degree we have to find the value of
2x=180-38
2x=142
x=142÷2
x=71</span>
