Answer:
x = 28 (So it takes 28 hours for the temperature to reach 0°C.)
y = -70 (So the temperature when the experiment begins is −70°C.)
Step-by-step explanation:
To find the the x value, you remove the y value or replace it with 0.
0 = 5/2x - 70
Next you move the variable.
70 (2/5) = x (multiply 70 by 2 to get 140 and divide that by 5)
And now you simplify to get:
28
To find the y value, you remove the x value or replace it with 0.
y = 0 - 70
And now you simplify to get:
-70
x = 28
y = -70
20) Answer is: x=76
21) Answer is x=15
Total amount of money invested - $11500
X +Y = $11500. ----------(1)
Total yearly interest for thetwo a/c is - $201
-0.03X + 0.04Y = $201
Form (1)
X = 11500 - Y
Substitute for X
-0.03(11500 - Y) + 0.04 Y = $201
-345 + 0.03Y + 0.04Y =201
0.07Y = 546
Y = 7800 at 4 %
Calculate X
X = 11500 - Y
= 11500 - 7800
=3700 at - 3%
Check
-0.03×3700 + 0.04 × 7800 = $201
-111 + 312 = $201
$201 = $201
