Curve Fitting using normal equations formulation of least squares

I am given an data table with values of x and y and supposed to approximate the relationship between x and y with a straight line y = a0 + a1*x. I must find the parameters using normal equations formulation of least squares. I have begun, but am unsure how to plot the curve?

My code is the following:

x = [20 40 60 80 100 120 140 160];  
y = [13 22 30 36 40 43 45 46];

% Normal equations formulation of least squares
A = [ones(size(x)) x]; 
b = inv(A'*A)*(A'*y);

[Dr. Bhavya]

use the command fplot(A)

Answer 1

[Matt J]

x = [20 40 60 80 100 120 140 160].';  
y = [13 22 30 36 40 43 45 46].';

% Normal equations formulation of least squares
A = [ones(size(x)) x]; 
yfit = A*((A'*A)\(A'*y));

plot(x,y,'*',x,yfit,'-')

Answer 2

[Stephan]

A = [20 40 60 80 100 120 140 160];
A = [A' ones(numel(A),1)];
b = [13 22 30 36 40 43 45 46]';
x = A\b;
fprintf('y = %.5f + %.5f * x\n', x(2),x(1))
test = x(1).*A+x(2);
scatter(A(:,1),b,'or')
hold on
plot(A,test)
hold off