Answer
x ≥ 68
Explanation
let that number be x.
(3/4) of x = (3/4) × x
= 3x/4
Decrease 3x/4 by 9,
3x/4 - 9
This expression is at least 42,
∴ 3x/4 - 9 ≥ 42
3x - 36 ≥ 168
3x ≥ 168 + 36
3x ≥ 204
x ≥ 68
Answer:
case 1
3x-7y=9
-4x+5y=1
using a graph tool
the solution is the point (-4,-3)------------------> one solution
case 2
y=6x-2
y=6x-4
two parallel lines
the system has no solution---------------> zero solution
case 3
-5x+y=10
-25x+5y=50
is the same line----------------> infinite solutions
Answer:
work is shown and pictured