The population of dolphins in the Pacific Ocean in 1990 was 243,000. It is decreasing every year by 2.3% due to pollution in our oceans. If this trend continues, how many dolphins will be there in 2030?

Year 1990, dolphins were 243,000
2.3% of 24300
= ( 2.3 / 100 ) * 243000
= ( 0.023 ) * 243000
= 5589
So every year, the population of dolphins decrease by 5589.

Now from 1990 to 2030 will be
= 2030 - 1990
= 40 years

Therefore, for a year = 5589 decrease
For forty years, it will be
= 40 * (5589)
= 223560 dolphins will be lost after forty years

The remaining ones
= 243000 - 223560
= 19440 dolphins will be left

Where's the rest of the

and y≤ -x +4 .

step-by-step explanation:

we are given a graph for system of inequalities.

in order to write the system of inequalities for the given graph, we need to find the inequality for each of the line separately.

let us find the slope of dotted line first.

taking two coordinates on the graph.

let us say (0,0) and (3,1).

let us find the slope of the line now.

slope of the dotted line would be =.

y-intercept of dotted line is y=0 only.

plugging slope m= and b=0 in slope-intercept form y=mx+b, we get

.

the line is shaded up of that dotted line.

therefore, for shading up we would take greater than inequality symbol > .

and because it's a dotted line we would take only > symbol in place of = sign in above equation of line.

therefore, inequality for dotted line would be

.

let us take two points (3,1) and (0,4) on the solid line.

slope of the solid line would be =.

for the solid line we have y-intercept b= 4.

plugging slope m= -1 and b=4 in slope-intercept form y=mx+b, we get

y = -1x + 4.

the line is shaded down of that solid line.

therefore, for shading down we would take less than inequality symbol < .

and because it's a solid line we would take ≤ symbol in place of = sign in above equation of line.

therefore, inequality for solid line would be

y≤ -x +4 .