to print following pattern

1 x 8 + 1 = 9

12 x 8 + 2 = 98

123 x 8 + 3 = 987

1234 x 8 + 4 = 9876

12345 x 8 + 5 = 98765

123456 x 8 + 6 = 987654

1234567 x 8 + 7 = 9876543

12345678 x 8 + 8 = 98765432

123456789 x 8 + 9 = 987654321

[Alex Mcaulley]

What have you tried so far?

Answer 1

[Rik]

You mean like this?

for k=1:9
    a=str2double(char('0'+(1:k)));
    b=a*8+k;
    fprintf('%d x 8 + %d = %d\n',a,k,b)
end

Answer 2

[Stephen23]

Three lines, no loop, and only basic numeric operations used:

>> X = 1:9;
>> Y = floor((137174210/1111111111)*10.^X);
>> fprintf('%d x 8 + %d = %d\n',[Y;X;Y.*8+X])
1 x 8 + 1 = 9
12 x 8 + 2 = 98
123 x 8 + 3 = 987
1234 x 8 + 4 = 9876
12345 x 8 + 5 = 98765
123456 x 8 + 6 = 987654
1234567 x 8 + 7 = 9876543
12345678 x 8 + 8 = 98765432
123456789 x 8 + 9 = 987654321

See also: https://oeis.org/A057137

[KALYAN ACHARJYA]

Auu.. Matlab Master ..Without Loop..Great @Stephan +1

Answer 3

[KALYAN ACHARJYA]

Today I lerned this polyval function, thats why I have posted 2nd answer, although the correct answer already given by @Rik

for i=1:9
value=polyval((1:i),10);
result=value*8+i;
fprintf('\n  %d x 8 + %d = %d',value,i,result);
end

1 x 8 + 1 = 9

12 x 8 + 2 = 98

123 x 8 + 3 = 987

1234 x 8 + 4 = 9876

12345 x 8 + 5 = 98765

123456 x 8 + 6 = 987654

1234567 x 8 + 7 = 9876543

12345678 x 8 + 8 = 98765432

123456789 x 8 + 9 = 987654321

[Rik]

That's nice lateral thinking with polyval. Note that our answers return different answers after 9:

%my answer:
NaN x 8 + 10 = NaN
%polyval:
1234567900 x 8 + 10 = 9876543210

That is caused by my trick with char. If you avoid that, you can also generate this:

12345678910 x 8 + 10 = 98765431290

%replace this:
a=str2double(char('0'+(1:k)));
%with this:
c=cell2mat(cellfun(@num2str,num2cell(1:k),'Uni',0));
a=str2double(c);

[KALYAN ACHARJYA]

Yes @Rik Thanks